Wikipedia talk:WikiProject Mathematics/Archive2011

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Jan 2011


Rychlik (talk · contribs · deleted contribs · logs · edit filter log · block user · block log), no doubt an otherwise well-intentioned editor, does appear to be adding material that is unduly self-promotional. He has already been warned of a potential COI, but perhaps further action is needed? Specifically of concern are the articles Marek Rychlik, Rychlik's theorem, and Chordal problem, all of which appear to assign undue significance to the editor's own research. I thought I should post here to solicit input on the best way to handle this constellation of articles. One possibility that seems reasonable to me is to delete Marek Rychlik and Rychlik's theorem, possibly merging some content from Rychlik's theorem to Chordal problem. Sławomir Biały (talk) 14:47, 28 November 2010 (UTC)

Most recent contribs include homoclinic connection, which has long been needed, and now appears to be a workable start. I'd recommend letting things slide for a while, and getting him comfortable with editing WP in general, rather than scaring him off with contentiousness. I suspect that many start by editing WP pages close to their heart, before showing broadened interests. Even I resisted but eventually succumbed to the urge to mention my own thesis work in an article somewhere :-) linas (talk) 05:36, 29 November 2010 (UTC)
One particular issue that strikes me is the need to establish that Rychlik's solution to the equichordal point problem is actually known as Rychlik's theorem. Almost all of the independent references currently in that article pre-date Rychlik's solution and so cannot be a source for that name. I have asked for a reliable source at Talk:Rychlik's theorem, but that request has so far gone unheeded. Gandalf61 (talk) 11:39, 29 November 2010 (UTC)
... and Ushiki's theorem, started by the same editor, has the same problem. Gandalf61 (talk) 13:16, 29 November 2010 (UTC)

Situation does look manageable. Would anyone inclined to intervene please note the key distinction: "potential COI" may be a hypothesis or it may be something that can be confirmed. But WP:COI relates fundamentally only to putting the encyclopedia's interests second, rather than first. Something like the discussion of whether equichordal point problem is a better title can actually be carried out compatibly with AGF. Charles Matthews (talk) 13:26, 29 November 2010 (UTC)

Indeed, and I hope I didn't seem alarmist. My chief concerns are that the autobiography is unsuitable (the subject is of borderline notability, and autobiographies are a COI as a rule) and the article about "Rychlik's theorem" (which is also a clear COI, although our standards on theorems are generally fairly relaxed). The other edits seem to be beneficial on the whole. Sławomir Biały (talk) 15:23, 29 November 2010 (UTC)

I am not convinced that redirecting Marek Rychlik to Rychlik's theorem was a good solution. We do have notability guidelines, and in this regard Marek Rychlik clearly fulfilled the criteria. Sure, the article was poor, but if anything I'd expected Rychlik's theorem to be renamed to equichordal point problem. Nageh (talk) 20:05, 6 December 2010 (UTC)

I'm not at all convinced that Marek Rychlik passes the notability guideline. He has one or two highly cited papers, but an otherwise fairly unremarkable career. Solving the equichordal point problem seems to be something that he himself is very excited about, but it does not seem to have generated any buzz in the wider mathematical world, so I don't think this rises to the required level of notability. I'm willing to be convinced otherwise, but at any rate people should not be writing articles about themselves to begin with, so as a short-term solution, a redirect seems fine. Sławomir Biały (talk) 15:37, 8 December 2010 (UTC)
Now on AfD. Sławomir Biały (talk) 16:38, 8 December 2010 (UTC)
AfD is fine with me. If your concern is insufficient notability, I do have to repeat the point that we have guidelines for when an academic is notable, and he clearly fulfills them. Regarding your disregard of his solution on the equichordal point problem, I want to point out this source and its introduction as a hint for notability. Anyway, I put my comments on the AfD page. Nageh (talk) 18:13, 8 December 2010 (UTC)
Indeed, I am certainly aware of the notability guidelines, and I see no evidence that he passes them. The book you cite mentions the subject, but only briefly in passing. And, at any rate, there are still the demands of WP:V, that sources must address the subject of the article in a nontrivial manner. If he truly is notable only for one thing, then WP:1E applies, and a redirect to Equichordal point problem is fully justified. Sławomir Biały (talk) 19:43, 8 December 2010 (UTC)

The other problem is that equichordal point problem is now a redirect to Rychlik's theorem. As I pointed out previously, I can find only a single source on Google that refers to this problem by "Rychlik's theorem". If anything, Rychlik's theorem should be redirected to the equichordal point problem article. Nageh (talk) 12:38, 9 December 2010 (UTC)

Yeah, it's just silly. The Rychlik's theorem page says that it solves the equichordal point problem, but then that link redirects to the page you're on. Meaning you don't know what the equichordal point problem is, and you don't know the motivation for Rychlik's theorem. It's a total COI for Rychlik to write articles about his own work. Fly by Night (talk) 14:15, 9 December 2010 (UTC)

I just found a paper on ZBMATH database (Wojtkowski, M.P., Two applications of Jacobi fields to the billiard ball problem, J. Differ. Geom. 40, No.1, 155-164 (1994)) which mentions Bialy's theorem and also Rychlik's theorem in the abstract. Now, two major questions arise: 1) is the user Sławomir Biały related to Rychlik in any way, if yes, did the relationship induce this discussion? 2) Independent of the first question, is one mentioning by another polish mathematician a proof for notability? I highly doubt that. DrPhosphorus (talk) 19:39, 18 December 2010 (UTC)

I have requested a renaming of Rychlik's theorem to equichordal point problem, followed by deletion of the article name Rychlik's theorem. Discussion here. Cheers, and a happy new year! Nageh (talk) 10:32, 31 December 2010 (UTC)

Input requested on recent breakage of Template:Su

I'd like to solicit input on the recent breakage of Template:Su in the Firefox 2.0 compatible browsers (there is a thread at Template talk:Su). I've just been told off that the ~20,000 current users of this line of browsers is not enough market share to consider fixing the template. The template is totally broken for users of this line of browsers (see the image on that discussion page for details), and a solution is very desirable. Potentially the template should be retired from use in favor of using <math> instead. Sławomir Biały (talk) 16:07, 1 January 2011 (UTC):

Does putting the whole thing (including the previous symbol) inside "nowrap" fix the problem? — Carl (CBM · talk) 16:30, 1 January 2011 (UTC)
No, the span actually has an embedded <br /> in it, and it breaks in Firefox 2.0 because it does not understand display:inline-block;. It used to work throuhg mozilla-specific CSS, which went deprecated in Firefox 3.0, but that caused problems for newer browsers (including Firefox 3.x), so the template was overhauled to use generic CSS. Firefox 2.0 is extinct; with making up only 0.43% of pageviews, we felt it is not worth fixing. EdokterTalk 17:08, 1 January 2011 (UTC)
I think the real question here is not "can we fix it?", but "should we fix it for 0.43% of users, if that means poorer experience for the rest?" in other words "backwards compatibility at what cost?".     — SkyLined (talk) 11:59, 2 January 2011 (UTC)
In this case, it seems to be an issue of fixing it for the ~5% who use Internet Explorer 6 at the cost of breaking it for the ~0.4% who use Firefox 2. If that's accurate, I think that going with the larger number of readers is the right choice. — Carl (CBM · talk) 12:26, 2 January 2011 (UTC)
I suppose it depends on whether it is still a priority for Wikipedia to remain usable for people running older systems. I know that in some areas (e.g., accessibility) obviously the need to be accessible to as wide a user base as possible is a major consideration. However, perhaps in other areas (e.g., the perennial debate about unicode) it is less of an issue. So, depending on how one prioritizes the matter, there are two ways forward: either accept that an appreciable number of users are going to be unable to read some of our articles, or use something else (e.g., <math>) instead of the template. Sławomir Biały (talk) 13:36, 2 January 2011 (UTC)
One problem with <math> is that it offers no accessibility features and you can't copy+paste it either; you would lock users with disabilities out, who cannot address their problem, in favor of users with insecure, outdated browsers, who are a liability to the net as a whole and the main reason why we have so many botnets. IMHO the later should be banned outright, but let's not get to that discussion :D. There are probably a number of ways to solve this specific issue in the tempalte, each with different drawbacks. This is why I think we should focus on the generic question of what level of backwards compatibility should we provide and at what cost to useful features.     — SkyLined (talk) 16:36, 2 January 2011 (UTC)
One can tell Wikipedia to format <math> as plain text, which will be accessible to every browser and works with screen readers. Math images cannot be copied and pasted but they work for everyone who can read images, again on every browser. Also the Su template loses the semantic information that a formula is mathematics, while the <math> tags will keep working (and improve appearance) when we eventually move to a better math system like mathjax or mathml. So there are several advantages to using <math> for formulas in a mathematical context. The majority of uses of Su seem to be for chemical symbols; only about 60 math articles use the template. — Carl (CBM · talk) 17:50, 2 January 2011 (UTC)
Side comment: I agree that mathjax is better, but I think it is likely to be broken on a much larger number of browsers. As I recall, mathjax seems to demand the latest version of everything, and doesn't seem to work on some of the more exotic browsers like Konqueror. Sławomir Biały (talk) 15:06, 4 January 2011 (UTC)


Hi, I was hoping to get some expert help. Operator (disambiguation) currently has over 100 incoming links, and we're having a tough time figuring out how to fix them. I'm suspicious that the disambig is missing a mathematics article or two. Could someone take a look at the mathematics articles in this list and give their opinion? Thanks, --JaGatalk 19:06, 3 January 2011 (UTC)

The word "operator", even when restricted to mathematics, has several meanings depending on context. Most of these meanings should be covered in Operator (mathematics) but I'm thinking that article should be merged with the main dab article; it's not in a very good state as it is. Meanwhile, the links to "operator" in math articles should be changed to link to an article with the specific meaning. I've done one or two but but it's not an easy task since it's often difficult to tell what specific meaning (if any) the author of an article had in mind.--RDBury (talk) 10:34, 4 January 2011 (UTC)
I did exactly the opposite about a month ago. The problem was that there was no article on operators on vector spaces, and the article operator (mathematics) (then just called operator) was horrible, mainly because its main contributors were programmers (even though there was already operator (programming) at the time) and non-specialists only familiar with arithmetic operations. You can look at the discussion page to get a feeling of how inadequate they were. That's why I think there must be a separate article on operators on vector spaces if only to protect it from unintentional vandalism, maybe under different title. — Kallikanzaridtalk 11:55, 4 January 2011 (UTC)
Part of the problem here is confusion between what programmers call "operators" and mathematicians call "operations" (e.g. the arithmetic operations "+", "-" etc.). So that some of the uses of the term "operator" which now link to operator, actually are referring to, and ought to link instead to, operation (mathematics). Paul August 12:26, 4 January 2011 (UTC)
I'm with you here, maybe we need to sketch a network of articles that will satisfy the community and lessen the confusion. — Kallikanzaridtalk 13:50, 4 January 2011 (UTC)

New Articles Are Being Created All The Time

Why does this project not use a project banner to identify articles that are within its purview? I put the banner on a somewhat new article's talk page while I was putting a value in |listas= and when I previewed the page I got the message that all the mathematics articles are in a List.

Lists have to be maintained manually. Categories populate themselves. The article I was attempting to tag is not on your list even though it has been around since October, 2010.

I am not doing drive-by tagging. I am working strictly by hand because of the low level of the quality of the sort values. I merely wanted call your attention to an article you seem to have ignored.

Happy editing! JimCubb (talk) 01:16, 5 January 2011 (UTC)

Which article are you looking at? The list is updated by a bot, not by hand, and we can investigate why the bot didn't find the article.
The reason we have not tagged every math article is that (1) it wouldn't be any more accurate than our list, anyway and (2) a bot cannot assess the quality or priority of an article, and the only point of our article tags is to carry this data. However, maybe the bot's list of categories needs to be tweaked. — Carl (CBM · talk) 01:35, 5 January 2011 (UTC)

There is a project banner on the talk pages of most math articles, I think.

Perhaps Movable singularity is what he's talking about. Michael Hardy (talk) 02:05, 5 January 2011 (UTC)

That article is on the list and has been around for years, though. — Carl (CBM · talk) 02:10, 5 January 2011 (UTC)
Károly Bezdek is the right age (and the talk page was edited by JimCubb recently). It's on the list too, though. Algebraist 02:13, 5 January 2011 (UTC)

Bezdek is the one I meant. I did not see him on the list and I apologize for missing him. The talk page of his article gives no indication that this project knows the article exists. JimCubb (talk) 02:21, 5 January 2011 (UTC)

It's on the list of mathematicians, which is separate from list of mathematics articles. Both are maintained by a bot using the article categories. If we tried to maintain the article talk page tags by hand, it wouldn't be any more accurate than the bot already is (how would we find the untagged articles, apart from categories?). — Carl (CBM · talk) 02:26, 5 January 2011 (UTC)

List of topics named after Karl Weierstrass

I've created a List of topics named after Karl Weierstrass.


  • Link to it from appropriate other articles. So far there's only a link from Karl Weierstrass.
  • Create all plausible redirects you can think of (I'll do the one with the eszett).
  • Expand it is appropriate.
  • Annotate it. After a link, one might put a comma followed by "a function used for turning elephants inside-out" (or whatever.........).
  • Add appropriate category tags (there's just one right now; maybe that's all it needs?).
  • Other appropriate editing as needed/desired.

So get busy and have fun with it. Michael Hardy (talk) 01:55, 5 January 2011 (UTC)

Movable singularity

Movable singularity has been prodded.

Do what you can with it. Michael Hardy (talk) 02:05, 5 January 2011 (UTC)

Someone's added a reference and de-prodded it. Quite possibly it still needs work. Michael Hardy (talk) 02:06, 5 January 2011 (UTC)
See three sections up. Algebraist 02:07, 5 January 2011 (UTC)

Proposed deletion of Movable singularity

Ambox warning yellow.svg

The article Movable singularity has been proposed for deletion because of the following concern:

A search for references found several references for the phrase, but multiple phrasing differences between sources and this article make impossible to Validate the accuracy of the article content

While all contributions to Wikipedia are appreciated, content or articles may be deleted for any of several reasons.

You may prevent the proposed deletion by removing the {{proposed deletion/dated}} notice, but please explain why in your edit summary or on the article's talk page.

Please consider improving the article to address the issues raised. Removing {{proposed deletion/dated}} will stop the proposed deletion process, but other deletion processes exist. The speedy deletion process can result in deletion without discussion, and articles for deletion allows discussion to reach consensus for deletion. JeepdaySock (AKA, Jeepday) 17:50, 4 January 2011 (UTC)

I've removed the "prod" tag, as this is certainly a notable topic. Paul August 18:10, 4 January 2011 (UTC)
The false positive is a bit worrying. The above template message suggests that there is some centralized place where a bunch of articles are being prodded en masse. This seems problematic. Also Jitse's bot seems to be out of commission at the moment, so we likely will have no idea if this affects other mathematics articles. Sławomir Biały (talk) 18:22, 4 January 2011 (UTC)
I will see what I can do about making a list of any math articles with prod tags. I need to get with Jitse to see if we can move his bot to the toolserver where others can help keep it running. — Carl (CBM · talk) 18:40, 4 January 2011 (UTC)
At the moment there are three math articles with prod tags: Proof Involving the multiplication of natural_numbers, Srđan Ognjanović and Q-class decomposition. — Carl (CBM · talk)
These are already on Wikipedia:WikiProject Mathematics/Current activity and it appears the bot was working as of the 2nd. One of the articles is also listed on the article alerts page, but 1 out of 3 isn't a very high coverage rate.--RDBury (talk) 22:03, 4 January 2011 (UTC)
I saw this discussion just after I made my addition to the page. You are missing the point of the prod tag on the article. There are no references on the article. The subject of the article may be notable but there is no justification of that in the article other than what appears to be original research. I have reinstated the tag.
There has been a history of empty threats on WP for some time. The no references tag has been in place, and ignored by the project, for years. A group of editors have noticed this problem and are trying to clean up the mess. JimCubb (talk) 01:28, 5 January 2011 (UTC)
Do not reinstate prod tags: it is a direct violation of policy. Algebraist 01:32, 5 January 2011 (UTC)
An "unreferenced" tag is not a "threat" - it's just a maintenance message, like "uncategorized" or "wikify". There's no deadline to handle these tags. If you wish to see more articles with references, the best thing to do is to add references. — Carl (CBM · talk) 01:41, 5 January 2011 (UTC)
Also, WP:BEFORE #9 has good advice: look for references before nominating an article for deletion based on a claim that the topic isn't notable. In this case, just a google books search would have shown that the topic can be found in many textbooks. — Carl (CBM · talk) 01:47, 5 January 2011 (UTC)
I heartily agree with Carl. A lack of references has not suddenly become a criterion for deletion. It certainly isn't the sort of thing that WP:PROD is supposed to be used for, which is for uncontroversial deletions. If, as indeed you say, "a group of editors" has banded together to start deleting unreferenced articles willy-nilly using prod, then someone needs to put a stop to it. Sławomir Biały (talk) 01:56, 5 January 2011 (UTC)

I see from their edit histories that Jeepday and JimCubb have been prodding any article that they cannot find references for. I have started a discussion about this at Wikipedia talk:WikiProject Unreferenced articles#Appropriateness of PRODding articles. Ozob (talk) 11:57, 5 January 2011 (UTC)

I found this discussion from the WikiProject Unreferenced articles thread. Anyway, I just wanted to clarify that it's my understanding Jeepday is working through the articles which have been unreferenced since 2006, not just any article tagged as unreferenced. Anyway, I'm glad the false positive was caught, and that the article is now sourced. PhilKnight (talk) 15:48, 5 January 2011 (UTC)
I am also glad that the I was wrong about the article, I wish I was wrong as spectacularly as this more often. The project goal is to find and add references to article that have been tagged as needing them the longest. The simple fact that articles are in the oldest Category:Articles needing additional references means that most are without anyone who cares to improve them, math articles are lucky to have a solid group like this. When a search for references does not find support for the articles content, every Wikipedian has an obligation to remove content that does not meet the expectations of Wikipedia. Now to the prod being discussed, more then just finding and adding a reference to an article, it is my basic expectation that the references should support the actual content of the article as written, and anything unsupportable should be removed. I looked and found multiple references, but was not able with validate the content to the reference enough to make me feel comfortable that the references supported the content. Unfortunately not every article can meet Wikipedia criteria even those written by the most trusted editors (see Wikipedia:Articles for deletion/Manar Group). The best anyone can do, is what seems like in best keeping with the goals of Wikipedia to maintain a high standard of content. I make every reasonable effort to contact anyone who might be able to show my prod is incorrect, (see Wikipedia talk:WikiProject Songs were I am mostly ignored) to the places I posted messages after this prod [1] [2] [3] [4]. If I can be of any help in referencing Math articles that are most in need of help let me know. JeepdaySock (AKA, Jeepday) 16:57, 5 January 2011 (UTC)
Your inability to find a reference which you were able to understand to support all of the article's content is not a valid reason for deleting an article, please see WP:DEL. If an article is about a notable topic, something your research must surely have confirmed, then the article should be improved not deleted. Paul August 21:31, 5 January 2011 (UTC)
Paul, actually it is "Articles for which thorough attempts to find reliable sources to verify them have failed", Which I believe you have quoted in part at least once. No where in Wikipedia (that I am aware) does it say that when a subject is notable the content of articles in not subject to WP:V, which requires that "readers can check that material in Wikipedia has already been published by a reliable source,", which I was not able to do. If you issue is with my judgment, or with Wikipedia policy this is not the venue to discuss it. I invite you to bring your concerns to my talk page or any appropriate venue. Jeepday (talk) 22:51, 5 January 2011 (UTC)
A google book search for "movable singularities" finds many textbook sources that look good. So my feeling is that your failure to find good sources cannot have constituted a "thorough attempt", because a thorough attempt would have easily succeeded in this case. Therefore, you did not have a valid reason for deleting this article. It is unsurprising that an editor who does not specialize in mathematics would not have the expertise to actually integrate the sources into the text, but that is different from what WP:DEL asks. —David Eppstein (talk) 23:12, 5 January 2011 (UTC)
I agree--Kmhkmh (talk) 00:16, 6 January 2011 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── WP:OWN Jeepday (talk) 01:00, 6 January 2011 (UTC)

Don't be ridiculous.TimothyRias (talk) 06:48, 6 January 2011 (UTC)
Yes, it is by no means true that mathematics here is a "walled garden", which would be a criticism worth answering. You know where we are, and this project is reasonably effective at dealing with queries about referencing. So please drop us a line in such cases. Charles Matthews (talk) 06:52, 6 January 2011 (UTC)

Möbius resistor

Should one of the math categories be added to the article titled Möbius resistor? Which one(s)?

(BTW, Oleg's mathbot has stopped adding new items every day to the list of mathematics articles. Jitse's bot still seems to be working, so it's Oleg's bot's fault we're not seeing anything new on the current activities page.) Michael Hardy (talk) 07:51, 6 January 2011 (UTC)

No, at best this is an application of Möbius strip to electrical engineering. It is not mathematics per se, unless you consider balancing your check book to be mathematics. JRSpriggs (talk) 12:45, 6 January 2011 (UTC)

Hoax warning

IPs (talk · contribs) and (talk · contribs) have been adding material which appears to me to be hoaxes, using actual (but absurd) papers by Patrick St-Amant as references. JRSpriggs (talk) 11:55, 5 January 2011 (UTC)

I don't think this is a hoax; it seems more likely to be a conflict of interest. The linked papers seem real, and one of them claims to have been published. However, I've removed the material from fundamental theorem of arithmetic and prime number because it doesn't appear to be notable, i.e., there are no reliable secondary sources yet. (I suppose that's a backhanded way of saying I don't think it's interesting; but it's also true.) I kept the reference at tetration because it's mostly about notation. I have no insight on the addition to continuum hypothesis, and I don't know what else might have been added. Ozob (talk) 12:22, 5 January 2011 (UTC)
Not sure about the hoax angle, but it could be routine WP:COI. This needs a wider base of sourcing before being used in an article.--♦IanMacM♦ (talk to me) 11:32, 6 January 2011 (UTC)
See Talk:Continuum hypothesis#No inverse powerset for my debunking of one of Patrick St-Amant's papers. JRSpriggs (talk) 05:28, 7 January 2011 (UTC)
The paper referred to in hyperoperation has such absurdities as "First, we devise a way to write the parentheses of a formula by using a superscript notation on the operations." (And even then, there doesn't seem to be a complete definition of his hierarchy of hyperoperations.) Even if published in a peer-reviewed journal, we would need to find someone who finds it notable and relevant. — Arthur Rubin (talk) 15:58, 7 January 2011 (UTC)

International Journal of Algebra

Has anyone heard of this impressively named publication? I can't find any article about it in WP, nor about its publisher, Hikari Ltd.

I ask mainly because a certain Pierre St Anant seems to have published in it, and the work is referenced in the hyperoperation article. A couple of Canadian IPs have been adding references to St Anant's ideas (largely sourced to arXiv publications) to various articles, including continuum hypothesis and fundamental theorem of arithmetic. My strong suspicion is that these are not appropriate for inclusion, but I have not read them carefully enough to be sure. --Trovatore (talk) 02:40, 6 January 2011 (UTC)

Oh, sorry, it's Patrick St-Amant, not Pierre St Anant. I see that JR has opened a related discussion above. --Trovatore (talk) 02:46, 6 January 2011 (UTC)

So no one's heard of the journal, then? --Trovatore (talk) 20:05, 6 January 2011 (UTC)

See I suppose it could all be a hoax but it would make a rather elaborate one :) Tkuvho (talk) 20:17, 6 January 2011 (UTC)
Oh no, I'm sure it exists. I found the online presence as well. What I want to know is whether anyone in the field actually knows it, whether it has a reputation, good or bad. --Trovatore (talk) 21:00, 6 January 2011 (UTC)
It's indexed in MathSciNet. So in that sense the field as a whole knows about it, at least. —David Eppstein (talk) 21:11, 6 January 2011 (UTC)
Well, again, knows that it exists. Come on. Surely there are some algebraists reading this. What's the journal's rep? --Trovatore (talk) 22:29, 6 January 2011 (UTC)
I find St Amant's ideas intriguing. Two different ways of formalizing a Grothendieck completion of set theory by adding "negative ranks" lead to opposite consequences as far as the status of the continuum hypothesis is concerned. This is sufficient reason to treat the contributor respectfully and avoid "hoax" rhetoric. Tkuvho (talk) 12:21, 7 January 2011 (UTC)
As far as the International Journal of Algebra goes; I've reviewed one paper for MathSciNet that was published there. It was okay, but nothing spectacular. I've never heard anything bad, nor anything good for that matter, about that journal. This may not say much, but looking at the Mathematical Citation Quotient in MathSciNet (this is the number of times articles in the journal were cited by articles indexed in MathSciNet, divided by the number of items published by the journal that are indexed in MathSciNet), the International Journal of Algebra has an MCQ of 0.04 (161 items published between the end of 2007 and the end of 2008, cited 6 times). For comparison, here is a random sampling of other journals (indexed going back to 2004): the Bulletin of the Iranian Mathematical Society has 0.15; the Bulletin of the Australian Mathematical Society has an MCQ of 0.32; Archiv der Mathematik is at 0.42; Proceedings of the Edinburgh Mathematical Society has 0.68; Communications in Algebra 0.36; Journal of Algebra is 0.58; Mathematical Sciences Research Journal is at 0.07. If you restrict, say, the Bulletin of the Iranian Mathematical Society to just 2007 (no items indexed for 2008), the MCQ is 0.15. Magidin (talk) 18:51, 7 January 2011 (UTC)

Prod notification

I can see that this group is motivated, and I would like to offer a couple of suggestions that may decrease the loss of articles to prod, no mater how you feel about them, you need take them into account.

  1. Not all math related articles are have templates on the talk page that will direct a Wikipedian to Wikipedia:WikiProject Mathematics, an example is Movable singularity, as a group you may want work towards putting your template on talk pages of math related articles, to make it easier for someone to inform you of a prod. (A more welcomeing response to receiving a notification, might be a good thing as well)
  2. While WP:AfD usually involves a group notification, there is no requirement nor function to ensure notification for {{PROD}}. There is a suggestion to notify author/project, but no requirement to do so. As group you may want to address those articles that are most at risk of a prod, unreferenced articles that have been tagged as needing references for prolonged periods. This usually involves comparing articles in categories under your knowledge base, to articles in Category:Articles lacking sources and/or Category:Unreferenced BLPs. There is no existing tool that simplifies this search, if you create one please drop a note at WP:URA so we can spread the word.

Cheers JeepdaySock (AKA, Jeepday) 12:00, 6 January 2011 (UTC)

What's that old saying: I divide my officers into four classes; the clever, the lazy, the industrious, and the stupid. Most often two of these qualities come together. The officers who are clever and industrious are fitted for the highest staff appointments. Those who are stupid and lazy make up around 90% of every army in the world, and they can be used for routine work. The man who is clever and lazy however is for the very highest command; he has the temperament and nerves to deal with all situations. But whoever is stupid and industrious is a menace and must be removed immediately! – General Kurt von Hammerstein-Equord —Preceding unsigned comment added by (talk) 13:20, 6 January 2011 (UTC)
I guess the smart and lazy solution is to check Wikipedia:WikiProject Mathematics/Current activity daily where a stupid but industrious bot lists all the prodded articles in mathematics category. --Salix (talk): 15:50, 6 January 2011 (UTC)
That is pretty cool tool, I have not seen any other projects that are using it. Can you get it to sort by date of tag so that those article that have been tagged as unreferenced longest can get attention first? JeepdaySock (AKA, Jeepday) 16:06, 6 January 2011 (UTC)
A few days ago I mistakenly thought Jitse's bot had gone down again (it seems to do that every year or two.....) but actually it's mathbot that has not been working since January 2nd. That's why the current activities page hasn't been notifying us of any new articles. Michael Hardy (talk) 17:58, 6 January 2011 (UTC)
JeepdaySock: I seem to remember that WP:Philosophy was setting up something similar based on our source code. CRGreathouse (t | c) 18:22, 6 January 2011 (UTC)
It is a great tool, Seem to require some technical skills to convert for each project. I am going to post in on the WP:URA talk page and see if I can get someone to make the solution easy workable for other project with less technically skilled help. JeepdaySock (AKA, Jeepday) 11:54, 7 January 2011 (UTC)

Weierstrass substitution

I've created a new article called Weierstrass substitution.

Tasks ahead:

  • Add references. (It has none yet. I'll soon add some.[Later note: There are now two. Maybe more are needed.] Others will know of some references that I don't know of, and they should add those.)
  • Add more categories if appropriate. Is there an algebraic geometry connection?
  • Expand the article. Maybe something on the geometry of the thing. Maybe I'll add a word or to on that later.[Later note: I've added a little bit about geometry.]
  • Carefully check details of the examples.
  • Other articles should link to it. Several already do. Probably more should.
  • etc.....

So get busy. Have fun. Michael Hardy (talk) 18:48, 7 January 2011 (UTC)

Help w/ new article Highest Weight Category

I just patrolled a new article Highest Weight Category and verified all that I could. I've confirmed the reference and updated it with a link to an online version, but this is far beyond my expertise. Could somebody familiar with representation theory review the article and confirm it is valid? Thanks. -      Hydroxonium (talk) 22:48, 7 January 2011 (UTC)

I did a few copy-edits and moved it to highest-weight category. As it stands, the article ends abruptly with an unfinished sentence. Michael Hardy (talk) 00:03, 8 January 2011 (UTC)
Thank you kindly. The article is way over my head, but it did seem sort of like an unfinished thought. The original creator had only this one edit, but was familiar enough with Wikipedia and markup language to create the article. So I'm not sure what to think about it. I was mostly concerned about it being a useful/valid article. Thanks again. -      Hydroxonium (talk) 01:51, 8 January 2011 (UTC)
I'll look into the literature and try to at least finish what's written, it appears that not only is the second axiom unfinished, but there is also a third, and a few other hypotheses. Certainly, Crelle's journal is a respected journal; additionally, Renner's book Linear algebraic monoids refers to the cited paper as "seminal" and Humphreys' book Representations of Semisimple Lie Algebras in the BGG Category O says the setup is "especially influential", so I think this article is legit. RobHar (talk) 02:48, 8 January 2011 (UTC)
WOW! Thanks very much, RobHar. I'm blown away. I just have to say thanks very much to everybody. Wikipedia is really lucky to have such educated and intelligent people helping. I really appreciate everybody's efforts and thank you all. -      Hydroxonium (talk) 17:28, 8 January 2011 (UTC)
Your welcome (and thanks)! RobHar (talk) 19:19, 8 January 2011 (UTC)

The article is still an orphan: no other articles link to it. Michael Hardy (talk) 18:13, 8 January 2011 (UTC)

Yeah, that's going to be harder to fix. I've added it as a "see also" in Weight (representation theory), but I don't know if there are any other current wiki articles that could link to it. It looks like a prototypical example of a highest weight category is the category of right A-modules where A is a "quasi-hereditary algebra" over the field k. It appears to also be related to Kazhdan–Lusztig theory and Bernstein–Gelfand–Gelfand's category O. But none of these are currently covered on wikipedia (AFAIK). (Also, thanks for the clean up on the article, I don't think I ever noticed that lower-case Greek should be italicized, probably 'cause they look so weird in html to begin with). RobHar (talk) 19:19, 8 January 2011 (UTC)

Articles names: singular or plural?

I'm not a mathematician, although I have a science background. I sometimes do proof-reading of some scientific Wikipedia articles, but mainly from the perspectives of English and readability rather than for technical content.

Various articles have brought me to a few pages such as "Bred vectors" and "Lyapunov vectors". It seems slightly strange that their titles use the plural form "vectors" rather than the singular "vector". By contrast, the title of (for instance) "Eigenvector", being in the singular form, seems much more natural.

Does the Mathematics wikiproject have a preferred convention on plural vs. singular in such titles? Shouldn't the title usually be singular unless there is good over-riding reason to use the plural?

(In all the above, my use of the word "singular" is in the English language "opposite of plural" sense, rather than any mathematical sense "singular vectors" sense!)

Would there be any objection to renaming, in particular, "Bred vectors" to "Bred vector" and "Lyapunov vectors" to "Lyapunov vector"?

Feline Hymnic (talk) 01:01, 8 January 2011 (UTC)

Wikipedia generally—not just the mathematics project—has a convention that titles are to be singular except when there is some special reason to use a plural. One such reason is nouns that are used only in the plural. Another is when the topic is a set of things, identified by a plural whose singular would refer to a member of the set—for example The Beatles or Maxwell's equations. Some polynomial sequences have articles that fit the latter description, e.g. Hermite polynomials. See Wikipedia:Article titles. There is a section where it says:
Use the singular form: Article titles are generally singular in form, e.g. Horse, not Horses. Exceptions include nouns that are always in a plural form in English (e.g. scissors or trousers) and the names of classes of objects (e.g. Arabic numerals or Bantu languages).
Michael Hardy (talk) 03:44, 8 January 2011 (UTC)
PS: I've just moved those two articles and fixed the links to them from within the article space. Michael Hardy (talk) 03:55, 8 January 2011 (UTC)
Eigenvector is actually a redirect to eigenvalues and eigenvectors. There was a recent discussion over the article's name here, which resulted in a renaming from singular to plural form in this case. Gandalf61 (talk) 06:56, 8 January 2011 (UTC)

Great. Many thanks. (As I typed my request, I was trying to think of an example from Maths where the plural would be the best; I was sure there would be some but they eluded me. So thanks, too, for jogging my mind with "Maxwell's equations".) Feline Hymnic (talk) 09:38, 8 January 2011 (UTC)

There are a few cases where it's better to use a plural since the the subject is about a relationship between two or more objects. For example we have Orthogonal polynomials since "Orthogonal polynomial" doesn't make sense.--RDBury (talk) 23:39, 8 January 2011 (UTC)

How many digits to show in irrational number articles?

The articles linked to in {{irrational numbers}} differ in the number of decimal places they show in the lead. Euler–Mascheroni constant shows 50 digit after the decimal point, Apéry's constant shows 45, Square root of 2 shows 65, Square root of 3 and Square root of 5 show 60 each, Golden ratio shows 10, Plastic number shows 17, etc. Should they be made consistent? I'd propose a not-too-large number of digits, e.g. 30. What do you guys think? --A. di M. (talk) 13:45, 6 January 2011 (UTC)

I'd say about 40 digits should be generally OK. However, some local considerations may apply. For example, the decimal expansion in the Plastic number article is squeezed between a fairly long radical expression on the left, and the bloody infobox on the right, so there is not enough room for additional digits. —Emil J. 14:14, 6 January 2011 (UTC)
I would suggest 3 (three) digits, with a link to more precise data. Tkuvho (talk) 14:20, 6 January 2011 (UTC)
This is an example of totally unnecessary and inappropriate standardization, as the difference between the proposed figures of 3 and 40 illustrates. How many decimal digits of a rational number would you list? Each is recurring, so why not all of them until the first repetition? Unhelpful in most cases, and the ratio provides an explicit formula. How about the golden ratio? Well, it has a dead simple continued fraction expansion. What about algebraic numbers? Should we list them all to the same precision as the most famous transcendental numbers, such as pi? I don't think so, and I suspect the best sources have a good sense how many digits is helpful.
Should they be made consistent? Short answer: No. Geometry guy 22:05, 6 January 2011 (UTC)
Maybe not a standard but guidelines may be useful. Probably a minimum of 8 or 10 would be good since that's what is shown on a typical calculator. Obviously there are some values that aren't known to that many digits. There is little value in doing 65 so I'd say that's excessive and krufty. How about we say don't include any more than can be found in Abramowitz and Stegun?--RDBury (talk) 01:10, 7 January 2011 (UTC)
Right, I don't see any need to enforce consistency for its own sake, but it wouldn't hurt to record the conclusions that have been reached in other similar cases and their reasons, rather than arguing from scratch every time. Every now and then someone goes to the pi article and dumps in 50,000 digits or so and is quickly reverted — clearly we don't want that anywhere. On the other hand, three seems sort of stingy, unless that's all that are known. I think around ten as a general rule. In cases where the decimal expansion itself has been the focus of lots of attention (really, I think that's only pi, although e might just sneak in), fifty would be OK. --Trovatore (talk) 02:09, 7 January 2011 (UTC)
For such numbers, we can have a section called "Decimal expansion" or something giving a hundred digits or so after the point, as IIRC pi does or used to do; I still think that giving more than about 30 digits in the lead, which is supposed to be a summary of the most important points of the article. --A. di M. (talk) 20:25, 9 January 2011 (UTC)
@ Geometry guy: Right now, the numbers of digits appear to be chosen randomly, rather than according to any criterion at all, so, whether or not standardization would be "totally unnecessary and inappropriate", the status quo isn't necessary or appropriate either IMO. --A. di M. (talk) 20:25, 9 January 2011 (UTC)
@ Emil J.: I've tweaked the lead of Plastic number so that now it could accommodate more digits (and IMO looks better even with 17 digits). --A. di M. (talk) 20:25, 9 January 2011 (UTC)

first order logic, second order logic,...

There is some confusion at these logic pages concerning the meaning of the term "first-order logic". There is a narrow sense of the term and a larger sense of the term. Thus, the page second-order logic adheres to the narrow sense, so that we find that "First-order logic uses only variables that range over individuals (elements of the domain of discourse); second-order logic has these variables as well as additional variables that range over sets of individuals." Meanwhile, the page first-order logic currently works with the larger sense, and moreover there is a bit of a back-and-forth going on, to which I have unfortunately contributed before realizing what the problem was. Tkuvho (talk) 12:36, 9 January 2011 (UTC)

Could you briefly summarize here what you see as the two senses of 'first-order logic' -- I'm not seeing it from the articles you reference, but that was after an admittedly casual scan. Thanks. BrideOfKripkenstein (talk) 16:52, 9 January 2011 (UTC)
I summarized it at Talk:First-order_logic. Tkuvho (talk) 17:24, 9 January 2011 (UTC)

New article Frenet-Serret frame

The redirect Frenet-Serret frameFrenet-Serret formulas was recently replaced with a new article that consists of content that is crudely copy-pasted from the articles Frenet-Serret formulas and differential geometry of curves. As far as I can tell, apart from the brief lead, no new content was added in the process (and all of the content still remains at Frenet-Serret formulas and differential geometry of curves). Should we have this separate article or should this content forking be reverted? It seems to me that the already existing article Frenet-Serret formulas is intended to cover both the formulas and the frame. Sławomir Biały (talk) 14:16, 9 January 2011 (UTC)

Comment: It looks like even the lead was copied from differential geometry of curves. Also the text of Frenet-Serret frame often doesn't make any sense, because it is a mish-mash from two different articles. Sławomir Biały (talk) 14:16, 9 January 2011 (UTC)
Even if I didn't know the article was recently split I'd suggest a merge. To be fair, it appears from the edit comments that the author was trying to create a merge of differential geometry of curves and Frenet-Serret formulas into a new article, but has only created a third article instead. So maybe the real question is whether there should be a single article instead of those two. My feeling is that there is a lot of material in the second article that's too specific to be included in the first, so that merge isn't a good idea.--RDBury (talk) 17:47, 9 January 2011 (UTC)

Move "operator" to "operator (mathematics)"?

If you have an opinion, please comment here: Talk:Operator#Requested move. Paul August 21:14, 9 January 2011 (UTC)

List of mathematics journals

Today, someone removed a large number of items from List of scientific journals in mathematics. I undid that edit. More eyes on the article and opinions on the talk page would be nice. — Carl (CBM · talk) 20:49, 11 January 2011 (UTC)

I also made a proposal there to create redirects from the titles of less-notable mathematics journals to that page. This will help with redlinks other places, too, for example there are two different articles that currently have redlinks to Topology and its Applications. We can discuss it on the list's talk page. — Carl (CBM · talk) 21:19, 11 January 2011 (UTC)


Mathbot doesn't seem to have added any new mathematics articles since January 2. I assume that the articles showing up lately in the current activity have been added manually somehow. Sławomir Biały (talk) 15:01, 13 January 2011 (UTC)

I have just sent this email to :
Mathematicians throughout the world have been
waiting patiently since January 2nd for you to
restore Oleg Alexandrov's access to his account
so that mathbot can continue its work.
Wikipedia's mathematics WikiProject is the most
successful, and possibly the most active, of all
WikiProjects, but there is this bottleneck.
Perhaps not the best way to do things, but that's
how it is for now.
The Project's "current activities" page has failed
to do its daily updates listing new articles since
January 2nd (except in cases where articles were
manually added to the list of mathematics articles).
I'll post a copy of this email to the project's
discussion page.
Prof. Michael Hardy
mjhardy (at)
(In case someone here doesn't know, new articles are (normally) listed daily at Wikipedia:WikiProject_Mathematics/Current_activity.) Michael Hardy (talk) 19:24, 13 January 2011 (UTC)
For those of us who aren't in the know, what's the background story?—Emil J. 19:47, 13 January 2011 (UTC)
In particular, I still have toolserver access, and access to the code that I arranged with Oleg in 2010. I didn't realize that this was a problem, and I might be able to fix things. But I don't know what's going on myself. — Carl (CBM · talk) 20:42, 13 January 2011 (UTC)
user:mathbot updates the List of mathematics articles daily. Then user:Jitse's_bot updates the Current activity page every day, including a list of new mathematics articles that have been added to that list. But mathbot stopped functioning on January 2nd. Its creator, Oleg Alexandrov can fix it if he can get access to the mathbot account. For some reason he can't do that, and has been kept waiting for a while. Michael Hardy (talk) 20:43, 13 January 2011 (UTC)
I sent Oleg an email. If someone can tell me what needs to be done on toolserver, I should be able to do it. Actually, I am going to try running mathbot by hand right now, and see what happens. Crossed fingers.
The toolserver admins are, in my long experience with them, actually very professional. The scale of the toolserver and the strict policies of Wikimedia Deutschland who sponsor it slow down the account acceptance process, but they have done their best to handle it. Again, I can get with Oleg and see if I can help navigate the process more smoothly. — Carl (CBM · talk) 20:56, 13 January 2011 (UTC)
I completely forgot that CBM had access to the bot. I had expected the toolserver folks to quickly restore my toolsever access but they are very slow. (The background story here is that I reinstalled by laptop OS, and I lost the ssh key with which to connect to the toolserver.) Oleg Alexandrov (talk) 21:04, 13 January 2011 (UTC)

I was able to run Mathbot myself, and it seems to have worked fine. For those who don't know, there is a "multi-maintainer project" named wpmath on the toolserver, which has the mathbot code. I am hoping to eventually get Jitse's bot there as well. The goal of this is to put us in a position that someone else can take over the code smoothly if the current maintainers leave. — Carl (CBM · talk) 21:47, 13 January 2011 (UTC)

You ran it, but I don't see any more new articles on the current activities page. What will it take to get all the articles created in 2011 listed there? We need that. Michael Hardy (talk) 22:40, 13 January 2011 (UTC)
I assume they'll show up within a day once the other bot (Jitse's bot) runs. —David Eppstein (talk) 23:03, 13 January 2011 (UTC)
Sorry....I'd momentarily forgotten about that. Michael Hardy (talk) 23:33, 13 January 2011 (UTC)

New articles

It seems that maybe some people involved in this project do not regularly look at Wikipedia:WikiProject Mathematics/Current activity and see the daily update on new articles. Because of the recent bot problems we have ten days of new articles simultaneously. Here are those new articles:

Action axiom, Amitsur–Levitzki theorem, Auslander algebra, Auslander–Reiten theory, Axis-angle representation, Bergman–Weil formula, Bivariate analysis, CP decomposition, Distortion problem, Einstein–Infeld–Hoffmann equations, Energy distance, Equichordal point problem, Erdős–Rado theorem, Euler calculus, Extension of a polyhedron, Fictitious domain method, Formally étale morphism, František Wolf, Gabriel's theorem, GraSM, Hadamard three-lines theorem, Harmonic pitch class profiles, Hermann Schapira, Highest weight category, Humphrey Baker, Ising critical exponents, John Baines (mathematician), John of Tynemouth (geometer), José Augusto Sánchez Pérez, Juan Luis Vázquez Suárez, Karl Johann Kiessling, Lagrange multiplier, Leah Keshet, List of four dimensional games, List of topics named after Karl Weierstrass, Loewy ring, Logicomix, Manohar Vartak, Mathematics Made Difficult, Mathematics and Computer Education Journal, Mathematics journal, Maurice Auslander, Memoirs of the American Mathematical Society, Metzler matrix, Mikhail Vasilyevich Menshikov, Mishnat ha-Middot, Multi-objective optimization, N=2 superconformal algebra, NK Model, Nakayama algebra, Nearly Kähler manifold, Octave (electronics), Olga Holtz, Opasnet, Open assessment, Operator, OptimJ, Orthodiagonal quadrilateral, Per comparison error rate, Pre-math skills, Press–Schechter formalism, Pseudoanalytic function, Real Analysis Exchange, Ribbon theory, Sheldon Axler, Solomon Gandz, Steven J. Cox, System Size Expansion, The Mathematical Classic of Sun Zi, The Ten Computational Canons, Thomas Little Heath, Tilting theory, Time-frequency analysis for music signal, Topology and its Applications, Transformation (function), Tricomplex number, Troposkein, Truncus (mathematics), Vector (mathematics and physics), Vladimir Ivanovich Mironenko, William E. Beckner
Acta Numerica, Advances in Mathematics, Alfred Loewy, List of mathematics education journals, List of mathematics journals, List of probability journals, List of statistics journals, Weak-star topology, List of genetic algorithm applications, Conformal group, Dieudonné determinant,

Happy editing! Michael Hardy (talk) 03:37, 14 January 2011 (UTC)

Struck a few that I think are OK. — Carl (CBM · talk) 21:30, 14 January 2011 (UTC)

Tricomplex number

Tricomplex number has been prodded. Is it worth keeping? Michael Hardy (talk) 20:48, 14 January 2011 (UTC)

Although the topic does sound suspect, there does seem to be some work by Silviu Olariu, for example this paper and a book "Complex numbers in N dimensions". — Carl (CBM · talk) 21:32, 14 January 2011 (UTC)
The only way this even begins to make sense is if one takes {1, i, j} to mean the distinct cube roots of one in the ordinary complex numbers. JRSpriggs (talk) 08:35, 15 January 2011 (UTC)
On 32-th sight this may not be as absurd as it appears on first sight. The source seems to be 2.1 of Olariu's book (published by North-Holland). What he describes is actually three-dimensional as a vector space over the reals. First I thought there must be a contradiction, but it turns out it's just a commutative ring, not a field. There are a plane and an additional straight line on which the tricomplex numbers have no inverse. Hans Adler 09:41, 15 January 2011 (UTC)
The review of Olariu's book in Mathematical Reviews gives some insight. I think Olariu's approach is worth a short mention at hypercomplex numbers. The article could then be turned into a redirect. Hans Adler 10:14, 15 January 2011 (UTC)
MR2003j:30002 --Qwfp (talk) 11:35, 15 January 2011 (UTC)

I've added some references to the article and a link from hypercomplex number saying "Tricomplex numbers - a 3d vector space over the reals, one of a family of systems of commutative hypercomplex numbers in n-dimensions over the reals.". Still not very notable, but neither are multicomplex numbers. (talk) 23:52, 15 January 2011 (UTC)

Transfinite induction

An anonymous editor at transfinite induction is under the remarkable impression that there is no successor step in transfinite induction. Please help out. --Trovatore (talk) 22:13, 14 January 2011 (UTC)

"The Penguin Dictionary of Curious and Interesting Numbers" by David Wells

Is this reliable? A certain editor is adding "facts" sourced to it, and in cube root, what was attributed to it about the history of the cube root of two was totally wrong. I'm asking here, before going to WP:RSN, as I'd like to see what other mathematicians have to say about it. — Arthur Rubin (talk) 18:19, 15 January 2011 (UTC)

My copy of the book is the "Revised Edition," so perhaps it's different from the edition used by the editor who inserted the purported fact about the cube root of 2. But I can't find any claim, in the edition I have, that Descartes was the one who proved the cube root of 2 to be irrational. (In fact, Descartes doesn't appear in the index.) The section about the cube root of 2, on page 17, focuses entirely on the duplication of the cube, and mentions only ancient Greeks. Page 34 is in the middle of the section about pi, and discusses a few attempts to square the circle, but doesn't mention Descartes or the cube root of 2.
About your question of reliability: Many of the entries in this book include references to other sources, so if there is a question about the correctness of a claim, hopefully there's a reference we can follow up. —Bkell (talk) 18:58, 15 January 2011 (UTC)
Investigating other recent additions by LutherVinci sourced to this book (it does appear that he is using a different edition, since the page numbers are different):
  • Quotation about 00 [5]: The relevant quote appears on page 9 of the Revised Edition, and says: "Like unity, 0 proves exceptional in other ways. It is an old puzzle to decide what 00 means. Since a0 is always 1, when a is not zero, surely by continuity it should also equal 1 when a is zero? Not so! 0a is always 0, when a is not zero, so by the same argument from continuity, 00 should equal 0. [Karl Menninger, Number Words and Number Symbols, MIT Press, 1969]".
  • 0.12345678910111213141516171819202122… [6]: Appears on page 9 of the Revised Edition.
  • Decimal expansion of  [7]: Appears on page 10 of the Revised Edition.
  • Joke cancellation of fractions equaling 1/4 [8]: Appears on page 10 of the Revised Edition.
  • Decimal expansion of [9][10]: Appears on page 10 of the Revised Edition, but no claim is made that this is an algebraic number.
  • Decimal expansions of , , and [11]: Appear on pages 10 and 11 of the Revised Edition, but nothing is said about their transcendentality.
  • Facts about 1/2 [12]: Appear on page 11 of the Revised Edition. The paragraph mentioning 6729/13458 and 9327/18624 has a reference to "[Friedman, Scripta Mathematica v8]".
  • Unknown status of the irrationality or transcendentality of Euler's constant [13]: Appears on page 12 of the Revised Edition, with a reference to "[Brent, MOC v31]".
  • Tau [14]: Page 51 of the Revised Edition states that 6.283185… is 2π, and says that it is the ratio of the circumference of a circle to its radius and also the number of radians in a complete circle (both of which are very elementary facts), but does not call it "tau."
  • Expression of as a series [15]: Appears on page 12 of the Revised Edition.
  • Importance of to sphere packing [16]: Appears on page 13 of the Revised Edition, where it is a direct quotation attributed to Rogers.
  • 1/ζ(3) [17]: Appears on page 13 of the Revised Edition.
  • [18]: Appears on page 13 of the Revised Edition.
  • Facts about 1 [19]: The fact that it is both triangular and pentagonal appears on pages 14 and 15 of the Revised Edition, though on page 15 it is written as, "Similarly, 1 is the smallest number that is simultaneously triangular and pentagonal. Also boring!" This is immediately followed by the sentence, "Indeed, 1 might be considered to be the first number that is both boring and interesting," but obviously this is a statement of opinion and is mathematically imprecise. The book also mentions that 1 is excluded from the primes, and gives a couple of intuitive justifications for that, but nowhere does it say, "1 is the smallest number of ways n objects can be arranged" (what is that supposed to mean, anyway—that 1 is the smallest factorial?).
  • Solution to Prince Rupert's cube [20]: Appears on page 16 of the Revised Edition, where it is attributed to "[Schrek, 'Prince Rupert's Problem', Scripta Mathematica v16]".
  • [21]: Appears on page 16 of the Revised Edition, but its transcendentality is not mentioned.
It appears that LutherVinci is attempting to go through the entire book and add nearly every fact to Wikipedia somewhere. —Bkell (talk) 19:36, 15 January 2011 (UTC)
I have the first edition of The Penguin Dictionary of Curious and Interesting Numbers (although mine's falling to bits now). It includes the following on page 34: "This [finding the cube root of two] is impossible with ruler and compasses, as Descartes proved two thousand years later in 1637". No reference is given, unfortunately. Interpreting this as implying the cube root of two is irrational, rather than constructible, was presumably an honest error.
The section about the duplication of the cube begins on p34, and includes: "The legend was told that the Athenians sent a deputation to the oracle at Delos to inquire how they might save themselves from a plague that was ravaging the city. They were instructed to double the size of the altar of Apollo." The change from 'altar' to 'temple' and omission of 'legend' here is down to the editor. As for the other discrepancies between this version and Doubling the cube#History (Athenians consulting oracle at Delos vs. citizens of Delos consulting oracle at Delphi), i'd personally be inclined to doubt Wells rather than that article's editors or Plutarch. --Qwfp (talk) 20:54, 15 January 2011 (UTC)
I certainly have no objection to including the legend, but LutherVinci was including it as fact, and I don't see why it should necessarily be in cube root, rather than in doubling the cube. In fact, I moved the information to doubling the cube, although I left it with {{cn}}. — Arthur Rubin (talk) 22:31, 15 January 2011 (UTC)

Duplication of content and general confusion

Please see Talk:Entailment#Duplication of content. - dcljr (talk) 19:55, 15 January 2011 (UTC)

Lapierre-Roy vectors?

Editor User:NewtonEin (as well as some anon ips) has been inserting material on Lapierre-Roy vectors and the Lapierre-Roy Law (such as in recent edits to Riemann zeta function). These two articles and related edits seem to be non-notable and OR. I'd be tempted to prod them, but I've never actually done this so I don't really know what it means. The first article appears to be renaming the concept of "infinite-dimensional vectors" while the second appears to be elementary estimates on values of the zeta function. Could anyone look at this? RobHar (talk) 03:18, 16 January 2011 (UTC)

Prodded, although might be of interest for large k. — Arthur Rubin (talk) 06:14, 16 January 2011 (UTC)

0.999...<1, a common misconception?

Is this a common misconception? You can comment at Talk:List of common misconceptions#0.999.... Tkuvho (talk) 03:41, 16 January 2011 (UTC)

Advances in Applied Mathematics

I've created a new article titled Advances in Applied Mathematics. As it stands, it needs work. Michael Hardy (talk) 20:35, 16 January 2011 (UTC)

Three math related FP nominations

After weeks of nothing there are now three nominations at once. Follow the links to see the discussions:

--RDBury (talk) 14:41, 17 January 2011 (UTC)

possible articles for clarity/accessibility improvement

  • metric tensor - this one was actually a featured article once. (a long time ago.) and commended for its readability (also a long time ago.)

post away. perhaps some day i'll find a better place to gather such a list.

also, another idea might be sort of a prize for clear and accessible articles. Kevin Baastalk 02:51, 18 January 2011 (UTC)

The first paragraph of that article seems perfectly reasonable, and it has a long introduction section. The topic is a basic part of differential geometry, which again is typically studied either at the basic graduate level or an advanced undergraduate level. And the article would still give some help to a person with some mathematical maturity who was willing to follow links. I don't think it's a goal we can or should attempt to make articles like that "accessible" to readers who don't have any of the background needed for the topic, for example the typical person off the street. A certain amount of mathematical maturity is going to be required for graduate-level mathematics, and there's nothing Wikipedia can do to change that. — Carl (CBM · talk) 03:08, 18 January 2011 (UTC)
okay, now you're just being silly. i understand the topic quite clearly i picked up a few books on them in my freshman year and it was quite clear and intuitive with just a basic understanding of calculus. the article is nothing of the sort. to give but an example "a rank 2 tensor". oh, you mean a matrix. well you know you could have said that. i happen to know that but say an engineer who hasn't taken a graduate course in topology abstract algebra and catgory theory is probably going to have a little difficulty with the intro. which is unfortunate because the concept is really quite simple and easy to understand. and easy to communicate. that article is a perfect example and it defintely stays on the list. Kevin Baastalk 03:25, 18 January 2011 (UTC)
The article does not seem to include the phrase "rank 2 tensor", and the first paragraph seems fine, like I said. But if what you mean by "accessibility" is replacing the word "tensor" with "matrix" in an article titled "metric tensor", personally I'm glad we don't have it. The article does say, in the last sentence of the lede, that relative to a coordinate system the tensor field can be reduced to a matrix field. — Carl (CBM · talk) 03:32, 18 January 2011 (UTC)
errr.. i'm sorry.. "nondegenerate symmetric bilinear form". i think that's what it refers to. you get my point. (i'm pretty sure i saw rank 2 tensor somewhere in the article if not the intro.) Kevin Baastalk 03:44, 18 January 2011 (UTC)
I don't get your point, actually. "Symmetric bilinear form" is a pretty elementary topic, and which is usually covered in an undergrad linear algebra course. I feel most students learn that before they learn what a matrix field on a manifold is. — Carl (CBM · talk) 03:52, 18 January 2011 (UTC)
Not to mention that it would be fairly difficult to define a metric tensor without relying on this concept. Fortunately, the article has a self-contained explanation of this concept. Yay! Sławomir Biały (talk) 03:59, 18 January 2011 (UTC)
(ec) Now you're wading into the tensor wars. Have fun with that.
To be a little less obscure — there is a deep division of opinion on how best to present tensors in general. The usual preference among mathematicians, and physicists of a certain stripe (e.g. the ones who wrote Gravitation), is to use a coordinate-free presentation. In my view there are good reasons for this; it is conceptually more fundamental. It is true, however, that the barriers to entry are a bit higher. --Trovatore (talk) 03:33, 18 January 2011 (UTC)

(ec)i beleived we compromised a long time ago by having 3 treatments: classical, intermediate, and component-free (modern). they can exist independantly just fine where the terms are different. though i'm sure there's overlap. Kevin Baastalk 03:44, 18 January 2011 (UTC)
The three-tiered solution was not ideal. I'm glad to see that there has recently been some progress towards consolidation. Sławomir Biały (talk) 03:59, 18 January 2011 (UTC)
Of course, the metric tensor article actually does it both ways, and explains nearly all of the jargon that it uses. But the real irony is that Kevin complained that there was too much jargon (e.g., covariant, tensor, etc.) in 2007 on the discussion page, and then someone added careful explanations of all the jargon along with the introductory section, and now he's complaining again because the explanations are difficult to understand. Sometimes that's just how it is with mathematics. Sławomir Biały (talk) 03:38, 18 January 2011 (UTC)
you're not listening and you're not being sympathetic. please if you're jsut going to be adversarial well it's not going to help so please let us just do our thing and improve the math articles for once. Kevin Baastalk 03:44, 18 January 2011 (UTC)
(ec) Also, the version of the article that Kevin seems to prefer is (presumably) this revision, which was the last time he meaningfully edited the article. I don't see how anyone can honestly claim that this earlier revision is superior. Moreover, it is equally clear to me that no revision of this article would have been featured by any meaningfully standard, contrary to Kevin's claim. Sławomir Biały (talk) 03:47, 18 January 2011 (UTC)
if that wasn't an edit conflict i'd feel i'd have to repeat what i just said. Kevin Baastalk 03:50, 18 January 2011 (UTC)
Given that you have commented on the talk page of metric tensor since 2003, what do you mean by "for once"? — Carl (CBM · talk) 03:52, 18 January 2011 (UTC)
clearly i am talking specifically about the metric tensor article which i have been working so hard on the past few months. (end sarcasm) Kevin Baastalk 03:53, 18 January 2011 (UTC)
(In response to Kevin's reply to me above) That's interesting advice from someone who avowedly no longer edits mathematics articles. Believe me, I am interested both in making our technical articles more accessible, and in making them serious reference works. I have edited hundreds of mathematics articles with these aims in mind. Telling off the very people who are trying to help is clearly not constructive. Are you sure you aren't trolling? Sławomir Biały (talk) 03:55, 18 January 2011 (UTC)
who's "telling off" anybody? i'm talking about improving article content and i would very much like to remain focused on that, please. are there any articles you'd like to add to the list? Kevin Baastalk 15:30, 18 January 2011 (UTC)
You just said "please let us just do our thing and improve the math articles for once", which I consider to be telling off. You have made very clear that you don't want my help. In fact, it seems to me that you aren't interested in the help of anyone that disagrees with you, which includes most of the folks here. Since these are the very people in the best position to improve the accessibility of our articles, it has become difficult for me to continue to believe that you seek genuine improvement. Perhaps you don't really understand what improvement entails. This is certainly suggested by the two examples you have so far provided, which went from amateurishly written, error-filled pieces to professionally written authoritative references on their respective subjects. Yet you seem to feel that this kind of progress is undesirable. Perhaps you aren't interested in professional quality writing—one obvious hallmark of which, incidentally, is being able to locate the SHIFT key on the keyboard. Sławomir Biały (talk) 15:46, 18 January 2011 (UTC)
Why are we humoring this obvious troll? (talk) 04:31, 18 January 2011 (UTC)
i wouldn't go so far as to call anyone on here trolls. i don't think they really mean to stand in the way of improving the articles. i'm guessing its largely status quo bias. and accusing people of things like that can itself be a problem and is generally considedered uncivil and bad form. for the sake of having a productive discuss, lets keep things focused on content. thanks. Kevin Baastalk 15:26, 18 January 2011 (UTC)
Uh, no genius, he was (correctly) calling _you_ out as a troll. (talk) 19:22, 18 January 2011 (UTC)
BTW (not to feed the troll), shouldn't Riemannian manifold be given more attention? — Preceding unsigned comment added by Kallikanzarid (talkcontribs) 07:29, 18 January 2011 (UTC)
see above. please try to remain civil and keep the discussion productive. thank you. Kevin Baastalk 15:35, 18 January 2011 (UTC)
Quite possibly, but the lede (which is all I read just now) seems perfectly accessible for the topic. — Carl (CBM · talk) 13:17, 18 January 2011 (UTC)
bear in mind, CBM, that you are not the general audience. "accessible" is a word that by its very nature refers to a general audience, not just you. it is clear that it does not seem perfectly accessible to some, even most people, as for one, most people don't have a graduate degree in mathematics. Kevin Baastalk 15:31, 18 January 2011 (UTC)
In a number of cases, such as Riemannian manifold, there is an easy solution, namely by providing a link to a more elementary page. Tkuvho (talk) 15:55, 18 January 2011 (UTC)
I'm very much against that solution in general. The lead should as far as possible should be written at an introductory level though there may be bits at the end of it to summarize more advanced bits of the article. Precise definitions can wait till later and one can have an introduction in the articles themselves. Dmcq (talk) 13:37, 19 January 2011 (UTC)
I agree with that as a general guideline, but in a hierarchical field like mathematics this is difficult to accomplish, and I think Riemannian manifold is a good example. Carl and I added a link in the lede to Differential geometry of surfaces, which is more elementary. I don't see how one can make Riemannian manifold accessible to a beginner (even with a calculus under his belt) without including a huge chuck of the material from Differential geometry of surfaces. My general suggestion would be to have an "Introduction" article for each high-level article such as Riemannian manifold. In this case, the article on surfaces can play the role of such an introduction. Tkuvho (talk) 13:48, 19 January 2011 (UTC)

Personally i've grown tired of this. there is way to much adversity to change making itself plainly obvious, despite what some people say. i just posted one suggestion here and see all the resistance that resulted. WhatAmIDoing was right: it's pointless; all it's good for is raising one's blood pressure. and i'm not really in to that sort of thing. it's sad, really (unfortunate), but what are you going to do? i can certainly find more productive uses for my time than dealing with this kind of blood-boiling resistance, utter lack of sympathy, or even listening, and worst of all condenscion, and getting nowhere. Kevin Baastalk 19:45, 19 January 2011 (UTC)

Miniclip, Jango, YouTube, ... just go have fun and don't worry about it. If you later decide to help out we'd be happy for another set of eyes, but the discussion at this point seems counterproductive. CRGreathouse (t | c) 20:04, 19 January 2011 (UTC)

Three questions for the lede

Tkuvho really gets credit for that link. I did copyedit the lede some. I think that the main questions that the lede needs to answer are the following, along with their answers from the lede of Riemannian geometry

  1. What is it? A Riemannian manifold is a real differentiable manifold in which each tangent space is equipped with an inner product that varies smoothly from point to point.
  2. What is it useful for? A Riemannian metric makes it possible to define various geometric notions on a Riemannian manifold, such as angles, lengths of curves, areas (or volumes), curvature, gradients of functions and divergence of vector fields.
  3. What field is it studied in? Riemannian geometry and differential geometry of surfaces

It is not always feasible to give a full answer in the lede, in which case we should still try to say something non-trivial (and at least nearly correct). For example, here are the answers from Kleene's T predicate:

  1. A particular ternary relation on natural numbers that is used to obtain a normal form for computable functions and to represent computability within formal theories of arithmetic.
  2. Telling whether a particular computer program will halt when run with a particular input.
  3. Computability theory.

The answer to #1 there is intentionally vague, but it's still explanatory. Especially in longer article, the lede also serves as a summary of the main points of the article. — Carl (CBM · talk) 14:01, 19 January 2011 (UTC)

The start of the definition section of the Kleene's T predicate looked quite reasonable to me as an introduction for someone who was about ready but didn't know anything about it, so it looked better to me as the easy bit of the lead. The what is it is true - but I eel it assumes you already know a bit about where you're going. WHich is all a bit wrong in ways because I'd have thought the more difficult bit would start with the definition section. Dmcq (talk) 14:42, 19 January 2011 (UTC)
I think there's an aspect of mathematical literacy that we may be somewhat overlooking here. In the sentence "In computability theory, the T predicate, due to American mathematician Stephen Cole Kleene, is a particular ternary relation on natural numbers that is used to obtain a normal form for computable functions and to represent computability within formal theories of arithmetic.", for instance, a mathematically literate reader may well see "ternary relation", think "I don't know what that is, so I'll leave it as a variable and come back to it later", or maybe click on the bluelink. This sort of writing, in which undefined terms are defined much more precisely later on, is standard in mathematics, and we're all used to it. A mathematically illiterate reader, or Kevin, may be more likely to think "I don't know what that is. This article is written too technically for me. I can't continue reading." So, more than is usual in articles written purely by and for mathematicians, we need to be careful here to avoid to the extent possible esoteric and technical terms at the starts of our articles, or when they are unavoidable to gloss them immediately within the text of the article rather than relying on the bluelink to do the glossing for us. (Of course, "ternary relation" is not the most technical term in that sentence, but I still think it would be an improvement in readability to write it as "set of triples" instead. It may be less precise that way but a little imprecision in the lede is not always a bad thing.) —David Eppstein (talk) 18:59, 19 January 2011 (UTC)
Carl, I like your set of three questions. I think they go a long ways towards addressing this problem. Furthermore, it's a simple, actionable goal: anytime someone complains, you can see if the three questions are answered. If you try them out on a few articles and continue to find them as promising as they look to me, then I suggest adding them to Wikipedia:Manual of Style (mathematics)#Article_introduction.
David, I think your example of "set of triples" is a good way to deal with technical terms. Another option is "ternary relation (set of triples)". We live in an unfortunately math-phobic world, and using simpler-sounding words will reduce the odds of scaring away the reader. WhatamIdoing (talk) 20:05, 19 January 2011 (UTC)
Yes, I like both of those wordings for ternary relation in that article. CRGreathouse (t | c) 20:06, 19 January 2011 (UTC)

Wikipedia:Wikiquette alerts#personal attacks and uncivil comments by User:TimothyRias

Just to note that is at least one attack at WQA basically at all the editors here (by Gregbard). Dougweller (talk) 12:51, 19 January 2011 (UTC)

I don't think there is much benefit in responding to things like that. Many editors here have seen this opinion from Gregbard before – it's far from the first time he has expressed it. The WQA thread seems to be mostly resolved, and if it is going to come to any resolution that will require completely uninvolved editors commenting on it, rather then involved editors needlessly prolonging the discussion. — Carl (CBM · talk)
I view practically all the discussion referred to as having just sucked away a bit of my life. Dmcq (talk) 13:53, 19 January 2011 (UTC)
But that's _IMPOSSIBLE_ Greg's a Goode Faithe Editor. You must have just read it wrong. (talk) 19:20, 19 January 2011 (UTC)
And someone said I couldn't take criticism! Kevin Baastalk 19:38, 19 January 2011 (UTC)

exterior algebra lead

Some encyclopedic editors are reverting my addition of a sentence in the lead at exterior algebra providing a link to more elementary pages that should be read first. Are they being too encyclopedic? Tkuvho (talk) 19:50, 19 January 2011 (UTC)

wikipedia is a great source of info for just about anything, with one exception: mathematics.

...for that I go to wolfram mathematica or planetmath or essentially anywhere else.

and it seems this state has been getting progressively worse throughout the years. as if there are a number of people who are actively making it worse.

something really needs to be done about making the articles coherent and accessible. badly.

Kevin Baastalk 17:36, 17 January 2011 (UTC)

So fix it. —Bkell (talk) 18:28, 17 January 2011 (UTC)
i'm not unfamiliar with that. i'm a long time contributor. surely you don't expect me to single handedly fix up every mathematics article on the wiki, do you? no, of course not. that kind of hand-wavey response is wildly out of proportion. Kevin Baastalk 18:42, 17 January 2011 (UTC)
I'm sorry, were you proposing a solution, or just complaining about the problem? If it's the latter, then I don't think my admittedly brusque response was "wildly out of proportion." —Bkell (talk) 19:30, 17 January 2011 (UTC)
both, actually, as you can tell simply by reading what i wrote. but your response was wildly out of proportion regardless. you see it is out of proportion because i am one person and the subject is a systematic trend throughout all of the mathematics articles. those two things are wildly out of proportion. furthermore whether i just say a complaint or make a criticism has no effect on the proportions of anything. Kevin Baastalk 20:11, 17 January 2011 (UTC)
Interesting. I have found the opposite to be true, pretty much without exception. Whenever I need a mathematics reference, I find that the best general purpose resources are typically Wikipedia and the Springer EOM, in that order. Mathworld's articles are too superficial, and often filled with technical errors and idiosyncracies that make it unsuitable as a mathematics reference. There are topics of enormous importance in mathematics that Mathworld doesn't even cover, or covers only minimally. Moreover, the references at mathworld are not very well-selected, often to tertiary literature, and so it is difficult to use Mathworld as a jumping-off point to consult the primary literature on a topic about which one wishes to learn more. (Although the same criticism could be made to many of our articles as well, I find that the standard of referencing in recent times is much improved over that of just a few years ago.) Finally, I can't imagine that anyone would seriously consider Planetmath as a viable alternative anymore. At any rate, most of the Planetmath content was already imported here ages ago. So perhaps it would help to turn this in a more constructive direction if you could be more specific. What role does a mathematics reference serve in your life, and why does Wikipedia fail to live up to that role? Can you give examples? Sławomir Biały (talk) 18:49, 17 January 2011 (UTC)
(ec) The thing with WIkipedia is that it has many contributors to keep an eye and a hand on it. If we spot a mistake, we can indeed fix it. If we spot one at Mathworld, we can send them an email once, twice, and three times—and then stop bothering since they never reply anyway. I gave up a long time ago, and whenever I see mathworld as a source for something here, I tend to hear an alarmbell somewhere. Probably a Pavlow thing. DVdm (talk) 18:57, 17 January 2011 (UTC)
(ec)We borged Planet Math a while back. Maybe that needs updating, but it's detail work the second time through. Rich Farmbrough, 18:58, 17th day of January in the year 2011 (UTC).
(ec) (reply to bialy) you see, none of what you just said speaks to what i said. that's great if you find wikipedia math articles make for a great collection of links ("well selected references") and what not. but among other things wikipedia is not a collection of links. now if you can recall the adjectives i used to describe what is lacking in the articles (as distinct from logically unrelated things that are not lacking), and relate your response to that, well that would be much more helpful. as you will see if you can find those adjectives, i _was_ specific in a _constructive_ direction. Kevin Baastalk 19:01, 17 January 2011 (UTC)
You wrote above:
wikipedia is a great source of info for just about anything, with one exception: mathematics....for that i go to wolfram mathematica or planetmath or essentially anywhere else. and it seems this state has been getting progressively worse throughout the years. as if there are a number of people who are actively making it worse.
I find the opposite to be true, and I have attempted to explain briefly some of the reasons. I don't believe that I ever mentioned links, but I agree that Wikipedia is not a collection of them. Our articles are generally much more detailed, with substantially more information than the corresponding Mathworld articles. From this perspective, our articles are better without a doubt, much more than a repository of links. Now coming to your last point, unfortunately it is not always easy to express this information in a way that will be accessible to everyone. It is certainly a worthwhile goal to do so as far as possible, and project members are by and large really interested in improving accessibility. Obviously this is not the only consideration: in particular, the depth and breadth of our coverage should not suffer as a result of our efforts to clarify. So to help guide your critique in a more useful direction, perhaps you could list some Mathworld articles that you feel express themselves better than the corresponding articles here, but yet have about the same depth of coverage. I think a reasonable goal is for our exposition of more elementary material to be as good or better than than at Mathworld. Sławomir Biały (talk) 19:23, 17 January 2011 (UTC)
thank you, bialy. in particular i've noticed the exterior algebra article is quite opaque. though i can't say in this case that wolfram is much better (i've just noticed over the years that it's much clearer and more visually intuitive which is why i use it instead of wikipedia). particulaly it starts off by barraging the reader with a bunch of esoteric terms, and in no apparent order. basic writing composition says you shouldn't put more than a fe ideas in a sentence and it violates that right there. it also clearly violates WP:LEDE. sure, you can have in depth information and all that, but that's what the body is for. the intro is for just that: to give a light introduction, and it should be accessible to readers who are not already familiar with the subject, as the clearly expressed by the style guidelines. Kevin Baastalk 20:11, 17 January 2011 (UTC)
on a more general note, there seems to be the presumption in many cases that accessibility is something more or less optional. and in any case takes a back seat to things like completeness and technical generality and so forth. however, it is easy to see that if something is not accessible, these latter things are entirely moot. accesibility and clarity is not merely optional, it is essential. it is a higher priority than making wikipedia something like a complete technical reference for every single aspect of every single proof of everything in only the most abstract all en-compassing terms etc etc. that is not what wikipedia is for. wikipedia is supposed to be a human readable encyclopedia, above all else. so what i'm suggesting here is a shift in priorities. i understand that some people may be quite adverse to this for their own reasons. but we are not writting for ourselves, we are writting for our audience. as such we should make a focused effort to write with respect to them. Kevin Baastalk 20:26, 17 January 2011 (UTC)
Well, people do have different priorities. We are all just volunteers after all, and I think that imposing a different set of priorities is likely to be met with the sort of resistance you are encountering. Sławomir Biały (talk) 13:11, 19 January 2011 (UTC)

The truth is that enWP's mathematics coverage is the go-to reference for those seriously studying the subject, i.e. graduate students. This is clear from the attitude on the MathOverflow site: search WP first, then ask us. In other words the articles this project curates are doing the work of a mathematical encyclopedia. It may be that we should look at criticisms that we are not performing other functions; but I for one am not prepared to accept such criticisms from User:Kevin Baas, whom I don't consider a reliable witness. Charles Matthews (talk) 19:27, 17 January 2011 (UTC)

lol! "being prepared" to "accept criticisms" from [insert name here], and whether they are "reliable witnesses"! omg, you can't possibly be serious! rotflmao! Kevin Baastalk 19:47, 17 January 2011 (UTC)
You haven't named a single article that you think could be improved. Ozob (talk) 19:49, 17 January 2011 (UTC)
thank you master of the obvious. Kevin Baastalk 20:02, 17 January 2011 (UTC)
Put up or shut up. Ozob (talk) 20:08, 17 January 2011 (UTC)
dude, learn some frickin' manners. what are you like a high school bully or something? geez. i don't condone that kind of stuff. i don't tolerate people speaking to others that way. Kevin Baastalk 20:11, 17 January 2011 (UTC)
For someone who claims on his user page to value critical thinking, your contribution so far has been disappointingly vague. Thank you for your discussion of exterior algebra above. If you have more evidence for your claim that Wikipedia's math articles are not "coherent and accessible", please provide it. Ozob (talk) 20:18, 17 January 2011 (UTC)

and yet he continues on in the same vein... as for critical thinking, i did not "claim that Wikipedia's math articles are not "coherent and accessible"". i said something logically related to that, yes, but that statement is a much stronger statement that is altogether logically different and does not follow. also being "vague", or more accurately, "general" does not preclude critical thinking. so there is another flaw in your argument. furthermore my goal is not to provide evidence of anything about wikipedia. that would be rather pointless and unproductive. but in any case, regarding the example i gave when asked nicely by baily... perhaps next time instead you could save yourself some breath and hardship by being a little more patient, or by taking after baily's much more practical approach of asking nicely. Kevin Baastalk 20:38, 17 January 2011 (UTC)

[22]. Bully yourself. You have been making assertions about the treatment of mathematics here for seven years, and I have yet to see you do any actual work towards improving it; you have certainly scrambled up the tensor topics, but forgive me if I don't count that as a plus. Charles Matthews (talk) 20:27, 17 January 2011 (UTC)

i'm not bullying anybody and i'm certainly not going to take orders from you. what you mean to say is that i've voiced similiar concerns something like seven years ago. which is quite different from implying that i've been doing it constantly for seven straight years. VERY VERY different. and of course i do not appreciate that. in fact i find it quite aggressive and inappropriate. (besides being an ad hominimem argument (among other things) and thus having no real practical value) and from the rest of what you say it's clear that you value your own opinion especially highly. certainly you consider your own opinion so much superior so that you can justify to yourself being offensive and aggressive to other people. needless to say this is also inappropriate. Kevin Baastalk 20:38, 17 January 2011 (UTC)
Compared to other areas I think the maths articles are quite well developed. For instance if you want to find out something like why using wax on a polyurethane coated floor is a bad idea or how to sharpen a chisel Wikipedia is definitely not the place to go. Comparing to Planetmath is silly. Mathworld can be a bit friendlier sometimes, that's something a person interested in improving the maths articles could help with. Dmcq (talk) 20:41, 17 January 2011 (UTC)
Gentlemen I vaguely remember we have a policy concerning the undesirability of personal attacks. As far as the subject of this posting is concerned, as I recall Charles developed a rather comprehensive reply a number of months ago, could you please provide a link? Tkuvho (talk) 20:46, 17 January 2011 (UTC)
(ec) yeah, that's what i'm talking about, making it a bit friendlier. i'm thinking maybe there should be some kind of community collaboration effort to make the articles "friendlier". that's why i brought it up on the project portal. on the note of the tensor articles, i'd like to take a breather from deflecting aggression aimed at me and say that i think that's an area where i feel there has been much improvement in this regard over the years and i'd like to thank everyone who contributed. Kevin Baastalk 20:47, 17 January 2011 (UTC)


  1. Wikipedia is not in competition with PlanetMath or MathWorld or any of these other places you mentioned. There is no need for Wikipedia math articles to be better than articles from those other sources. They are specialized resources focusing solely on math; Wikipedia is a general-purpose encyclopedia. If Wikipedia has better math articles than they do, great; if not, well, that's not our specialty.
  2. If you think PlanetMath or MathWorld has better math articles than Wikipedia, then use PlanetMath or MathWorld instead of Wikipedia. It won't bother us, I promise.
  3. Your suggested solution in your original post was apparently "something really neeeds [sic] to be done about making the articles coherent and accessible. badly." That's not a helpful suggestion. You aren't providing any specific ideas or proposals. You are basically just saying, "You guys have bad math articles and need to fix them!" That's not a solution—that's a complaint.
  4. We are volunteers here. We don't need to do anything.
  5. If you aren't happy with the state of Wikipedia math articles, you are more than welcome to help to improve them. That's why I posted WP:SOFIXIT. But simply complaining at the rest of us that you don't like the math articles here isn't going to solve anything. —Bkell (talk) 20:55, 17 January 2011 (UTC)

  1. Wikipedia is not in competition with PlanetMath or MathWorld or any of these other places you mentioned. There is no need for Wikipedia math articles to be better than articles from those other sources. They are specialized resources focusing solely on math; Wikipedia is a general-purpose encyclopedia. If Wikipedia has better math articles than they do, great; if not, well, that's not our specialty.
    we're not in competition with anybody. but that doesn't mean we can't look at the strengths and weaknesses of other sources and maybe learn some valuable insights about writing and presentation by doing so. as to our specialty, quite correct: it is not math articles, it is as you say, being a general purpose encyclopedia. which is kinda my point, actually. our math articles should be written as if we are a general purpose encyclopedia, not as if we specialized in math for mathematicians. Kevin Baastalk 21:08, 17 January 2011 (UTC)
  2. If you think PlanetMath or MathWorld has better math articles than Wikipedia, then use PlanetMath or MathWorld instead of Wikipedia. It won't bother us, I promise.
    oh yes, but they're not a wiki. i can't take the strengths of one and transfer it to another. with a wiki dictionary, that's at least theoretically possible. Kevin Baastalk 21:08, 17 January 2011 (UTC)
  3. Your suggested solution in your original post was apparently "something really neeeds [sic] to be done about making the articles coherent and accessible. badly." That's not a helpful suggestion. You aren't providing any specific ideas or proposals. You are basically just saying, "You guys have bad math articles and need to fix them!" That's not a solution—that's a complaint.
    i was more specific and suggested ways in which they could be improved. you see i just used the word suggestion right there. (well, the -ed version of it.) i'm surprised you missed them after actually quoting me on them. i suggested "making the articles [more] coherent and accessible". (edit:that is certainly a specific way of improving things. put otherwise "i strongly think the articles could benefit greatly if we focused more on ___." and that is clearly a solution. and not a vague unspecific complaint as you seem to try to parody it as.) i was trying to leave the discussion open for ideas, kind of brainstorming, instead of jsut taking control of it right away with my own. though i have stated it now, creating sort of a formal team for making articles "-friendlier", as somebody else put it. Kevin Baastalk 21:08, 17 January 2011 (UTC)
  4. We are volunteers here. We don't need to do anything.
    oh yes, i didn't mean to use the word like that. i though that was clear from the context. sorry. Kevin Baastalk 21:08, 17 January 2011 (UTC)
  5. If you aren't happy with the state of Wikipedia math articles, you are more than welcome to help to improve them. That's why I posted WP:SOFIXIT. But simply complaining at the rest of us that you don't like the math articles here isn't going to solve anything. —Bkell (talk) 20:55, 17 January 2011 (UTC)
    i have improved them. i know why you posted sofixit. (i'm not an idiot.) and again i'm not simply "complaining at the rest of us that you don't like the math articles ". that is a false characterization. which should be pretty obvious by now if it wasn't originally. Kevin Baastalk 21:08, 17 January 2011 (UTC)

Maybe we should start collecting these discussions, in a FAQ-type listing. It might be a much more efficient method of communicating this group's apparent disinterest in addressing this ongoing problem.

Someone complains that the math-related articles are needlessly opaque several times a year, and as far as I can tell, every single complaint gets blown off. Typically, the closest we come to a solution is someone inviting the complainants to magically know enough about the subjects to fix basic problems (e.g., the absence of a paragraph about "why anyone cares about this concept"). In my experience, identifying specific, concrete problems in specific, named sentences in individual, linked articles earns you exactly the same kind of dismissive response that vaguer complaints produce. I've personally seen a complaint about a basic grammar problem get dismissed, as if editors who work on math articles shouldn't have to use the level of English that one expects from a typical 12 year old.

So Kevin, let me assure you that far from the first person to complain about this problem, but unfortunately the people who appear to be primarily responsible for creating the problem are perfectly satisfied with the status quo, so complaining here will accomplish nothing except raising your blood pressure. WhatamIdoing (talk) 22:05, 17 January 2011 (UTC)

It's utterly ridiculous to compare WP math coverage with MathWorld and think it comes up short!! WP math articles are immensely superior to MathWorld. --Trovatore (talk) 22:13, 17 January 2011 (UTC)
The problem is that people complaining typically do so with a very aggressive voice and with an air of entitlement. The OP of this thread is a case in point, it is basically a troll. It appears the OP wanted nothing short than a flame war for his own entertainment. If not, he just has very poor people and motivational skills.TimothyRias (talk) 22:23, 17 January 2011 (UTC)

breaking up

@WhatamIdoing: I, for one, have on many occasions addressed issues raised by users concerning the accessibility of math articles. Typically, these occur on talk pages of the corresponding articles, in which case they are much easier to address. I'd venture to say that most accessibility issues raised on this discussion page are rather vague and hence much harder to address appropriately. It is true that it would difficult for the one person raising the issue to fix everything him/herself, but with a complaint like "almost all math articles on wiki are incoherent and inaccessible", it's not like the ~20 regulars who hang out in this forum can fix everything either. Other times I've disregarded a request to improve accessibility are along the lines of "I have a college degree in engineering, and even I don't understand what the article Class formation is saying", and while that article could be improved and made more accessible, knowing college level math is by no means sufficient to have any idea what that article is about.

As for the discussion at hand, the OP's original comment was certainly not the best way to approach this issue. In fact, the only phrase the people in this forum are likely to somewhat agree with is that accessibility needs to be improved. I, for one, am pretty sure most of our articles are "coherent", and I'm only on wikipedia because I find planetmath and mathworld mostly unhelpful. I'm also fairly certain our articles have not been getting worse. (You could argue that maybe the number of good ones as a percentage of the whole is going down, but only because there's an increasing amount of articles, so that's not a very good measure). Finally, while there are people making articles actively worse, they are presumably not the people from whom the OP is asking for help, so there's no need to leave a lingering potential insult lying around. So, as I said, there is at most one thing out of six that the OP said initially that participants here could identify with. That's not a good score if you're trying to get people to help you. RobHar (talk) 22:39, 17 January 2011 (UTC)

(ec) i don't know who you're talking about, unless "OP" refers to "original poster", which is pretty transparent, i.e. you might as well use the person's name. it doesn't make it any less of a personal attack, which is strictly prohibited. and it is very overt and egregious and i strain to not state myself more plainly for fear of the same. furhtermore it is assuming bad faith and it is talking about editors and not content. all rather egregious contraventions of policy and simply good form. and the personal attacks on me are certainly most egregious and i do not appreciate them and in fact take great offense to them. i presume in good faith that that is not your goal, of course (and well, that it would be quite ironic if it were). so perhaps as a sign of good faith you could offer some repair, as it were? Kevin Baastalk 22:43, 17 January 2011 (UTC)
If you take such great offense at insult, you might consider not starting off a thread with one. I'm prepared to offer an apology, if you first apologize to this community as a whole. TimothyRias (talk) 22:54, 17 January 2011 (UTC)
i'll take that as a no. be that as it may, i am reporting you on WP:ANI. Kevin Baastalk 22:59, 17 January 2011 (UTC)
In case anyone cares: the actual report appears to have been at Wikipedia:Wikiquette alerts#personal attacks and uncivil comments by User:TimothyRias. And Kevin appears to have failed to follow proper Wikiquette himself, by not notifying the subject of his report more explicitly. —David Eppstein (talk) 23:27, 17 January 2011 (UTC)
opp, sorry i missed that. thanks. though notifying me more politely on my talk page (and perhaps being a bit ore patient and less accusatory. (first time i've used the new process.)) would be... well looks like we both screwed up. Kevin Baastalk 23:45, 17 January 2011 (UTC)
Maybe. But I think in general, it would be an improvement for you to spend more energy on improving articles and less on trying to figure out who screwed up where. —David Eppstein (talk) 00:48, 18 January 2011 (UTC)
oh but when i screw up i should certainly like to know. and when something bothers me i should much rather politely say so then just bottle it up or be crass about it. anycase i don't have much of an idea on who screwed up what nor do i care as long as everyone's being honest and fair and decent. i just want to find ways in which we can make the content better, preferably with as little squablling as possible. Kevin Baastalk 01:19, 18 January 2011 (UTC)
(afters 2nd paragraph was added) please stop refering to me in the third person. i am right here. it is rather transparent and impolite. there are areas where the articles have improved in accessibility and there are areas hwere they have gotten worse. and i do with all my heart hope that the people who are giving accessibility and the like short shrift and responding most obstinately at the suggestion that there might be a better way are precisely the ones who take these things MOST to heart. for anything less would be a rather hopeless state of affairs. perhaps i'm being too optimistic; perhaps i am putting a little to much faith in people here. i could be. but its certainly more productive then constantly ridiculoius, attacking, and diminishing the honest and selfless concerns of a "original poster". Kevin Baastalk 22:51, 17 January 2011 (UTC)
For the record "OP" stands for both "opening post" and "original poster". Its use is well established netiquette, and can not really be regarded as impolite.TimothyRias (talk) 22:57, 17 January 2011 (UTC)
it is not the term that is polite or impolite but the way in which it is used. that is well established etiquette'. Kevin Baastalk 22:59, 17 January 2011 (UTC)
It seems as though I am one of the people that you are unhappy at for using the designation "OP". I can assure I meant no harm, nor was I attempting to be mysterious, I simply meant to use it as a completely standard way of referring to the person who started the topic. I was referring to you in the third person because, as the "@WhatamIdoing" at the beginning of my post indicates, I was responding to User:WhatamIdoing. RobHar (talk) 23:11, 17 January 2011 (UTC)
Thanks. :) you make some good points, robhar. i still think we might benefit from some kind of more formal effort in this regard. maybe like forming on open "team" that focuses on one article at a time. in the same matter as "article improvement drives", it could be more along the lines of accessibility and "friendliness" improvement. Kevin Baastalk 23:27, 17 January 2011 (UTC)
oh, and by "coherent", what i mean is, well i guess that kind of ties into accessibility, but it's more to do with the order in which ideas are presented rather than the language used and such. articles sometimes seems a bit fragmented to the unacquainted and can sometimes be made more pedagogical. so that's what i meant. probably not the best word choice, best i could think of at the time. Kevin Baastalk 23:42, 17 January 2011 (UTC)
(ec) I was going to point you to Wikipedia:Mathematics Collaboration of the Month, but it looks like you're already aware of it. It's been dead for a couple of years now though, and it's unclear whether it would survive if reanimated. You do raise an interesting variant: a collaboration of the month that wouldn't necessarily attempt to add material (i.e. depth) to an article, but try to make an article more accessible. That could have appeal, I dunno. One problem is that it's easier to add depth to any article than to make it more accessible: most mathematical sources deal with the raw facts and spend little time on accessible narrative. Though for some of the more basic topics, this would be easier. Are there specific articles that you think would be good articles with which to begin such a project? RobHar (talk) 23:52, 17 January 2011 (UTC)
good question. let me think on that. in general i would think it would make sense to start from more elementary and go up. or if some people find articles that they think particlarly opaque, provided the content isn't too esoteric to begin with... how did collaboration of the month do it? Kevin Baastalk 00:34, 18 January 2011 (UTC)
For COTM, people just nominated articles and at the end of the month the article with the most votes became the COTM (if it had at least 3 votes). I think there was a discussion on the talk page of that project containing suggestions on how to improve the process. Still give some thought to some first examples of articles and if they work out that could get the ball rolling. RobHar (talk) 02:34, 18 January 2011 (UTC)
Rob, I'm willing to agree that Kevin has failed to win friends and influence people, but in my experience, the presentation wouldn't have affected the outcome.
If you want to change my mind, then I invite you to provide me with links in WP:MATH's archives that prove the existence of brilliantly helpful, or at least sympathetic, responses to this kind of general complaint. I can supply you with links to more examples of the defensive, insulting, and self-justifying responses that we saw today, but that doesn't sound very uplifting. Can you provide good examples of discussions that show this group (and not merely one editor) responding helpfully and kindly to criticism about unnecessarily obscure content? WhatamIdoing (talk) 01:47, 18 January 2011 (UTC)
I don't think I claimed that there were cases of sympathetic responses to general complaints. On the other hand, I don't remember any reactions as adverse as the current one. RobHar (talk) 02:28, 18 January 2011 (UTC)
Thank you. One of the people at wikiquette alerts seems to think i'm full of s**t. I am done talking to him. Kevin Baastalk 02:42, 18 January 2011 (UTC)
Examples in the form of this talk page complaint at a specific article leading to this improvement to the article are not hard to find. Examples of a constructive response to someone coming to the project talk page and telling us our articles are all bad without telling us which articles he's talking about are likely to be rarer, though. —David Eppstein (talk) 01:57, 18 January 2011 (UTC)
I'm saying -- and i thought i already made this clear -- that we should do some thing(s) more systematic. the FAQ recently posted is a good example. Kevin Baastalk 02:20, 18 January 2011 (UTC)
Could you give some examples of unnecessarily obscure content? The only link I saw above was to exterior algebra, which is an obscure topic to begin with. It's a graduate-level topic, not covered in the typical undergraduate curriculum except possibly at the very strongest universities. But that article does not seem particularly obscure to me, and I am neither a geometer nor an algebraist, and only have a basic graduate background in those areas. So I'm not sure whether the criticism is simply that we have articles on graduate-level topics – I consider that a strength, not a weakness. — Carl (CBM · talk) 01:57, 18 January 2011 (UTC)
The other thing that makes the complaint hard to understand is that Wikipedia is well-regarded in academic math circles as a basic reference. Many mathematicians I know use it as a way to check basic definitions in fields they aren't familiar with. I have seen talks where the speaker actually quotes definitions from Wikipedia (although that would be unlikely in an actual paper). So, without more detail, it's hard to understand a vague claim that Wikipedia is not a good reference for mathematics topics. — Carl (CBM · talk) 02:00, 18 January 2011 (UTC)
Well there's the misunderstanding right there. i didn't say it wasn't a good reference. i thought i already cleared this up. i said some of the articles could use some more pedagogical prose (to say it differently). which is something altogether different. the back pages of a calculus book is a good reference, but it doesn't tell you anything about what anything really means, visually. Kevin Baastalk 02:20, 18 January 2011 (UTC)
We have to avoid most pedagogical prose because it violates WP:NOR (and WP:NOT). Being a textbook isn't our mission, we just try to be a reference. I generally don't remove mild OR when I see it, unless it's far over the line, but at the same time it's not something that careful editors are going to add. — Carl (CBM · talk) 02:22, 18 January 2011 (UTC)
yeah, it's a tricky issue. i believe wp:nor makes exceptions for trivial things and a lot of stuff, esp. at more basic levels, are quite trivial. there is a balance and it's i think further in the prose direction than a lot of people think. we don't try to be a reference, we try to be an encyclopedia. big difference (and i know an encyclopedia is a type of reference, that's not what i mean). in order to do that we have to be descriptive and prosiac, just like other encyclopedias are (maybe briticannica or comptons or something is a better example than wolfram). otherwise we're not really doing our job. that's all i'm saying. i understand the difficulties. i didn't really think it's that strict where we can't do a good job at it. Kevin Baastalk 02:32, 18 January 2011 (UTC)
On one hand, exterior algebra is not something at a "more basic level". On the other hand, we already far exceed Britannica in our coverage. For example, try to find any coverage of group theory there – and that's taught to virtually every pure mathematics undergrad. Using Britannica as a mathematics reference after high school is essentially impossible.
On another hand, we can't hope to write textbook style presentations, complete with many original examples, pedagogical remarks, exercises, etc. Personally, I don't see that exterior algebra as particularly, bad; the first paragraph is accessible to anyone with half an undergraduate degree, and it has a lengthy "examples" section. It's not an elementary topic, and there are no low-level books on it. It's unrealistic to expect Wikipedia, which has absurdly high restrictions on sourcing, to write low-level articles on topics for which the only references are at the graduate level. — Carl (CBM · talk) 02:44, 18 January 2011 (UTC)

is hard to do

──────────────────────────────────────────────────────────────────────────────────────────────────── I agree with the OP that the maths articles do let WP down. I've a maths-physics background, and the maths articles fall below the physics articles in clarity, IMO. Some are good, but a lot are really bad in that they don't communicate the concepts to all audiences. They look like they are written by PhDs for PhDs. A good article can communicate on many levels, explaining the concepts at an elementary level and more advanced levels. -- cheers, Michael C. Price talk 10:52, 18 January 2011 (UTC)

What is the "elementary level" of exterior algebra? We don't have a goal of writing popularizations of topics like that – it would be silly to try to write that article in a way accessible to an 8th grader. These topics are primarily of interest to people at the graduate and advanced undergraduate level, and it's perfectly appropriate to write articles that are aimed at such an audience, rather than trying to address some nebulous concept of "all audiences". On the other hand, articles like addition are written in a much more accessible way, as they should be.
As Charles Matthews and I have pointed out, Wikipedia is used very frequently as a reference by practicing mathematicians. I value that much more than I value the ability of a random 8th grader to read exterior algebra. — Carl (CBM · talk) 13:15, 18 January 2011 (UTC)
Well, there is some truth to the statement that a significant share of our articles can and should be more accessible, without really sacrificing much in the way of usability as a serious reference work. But obviously the issue of making articles accessible is one of priorities. There are only so many people who regularly edit Wikipedia mathematics articles, and still fewer that are talented enough as expositors to be able to make any topic accessible for a general audience. Naturally, we are going to prioritize which articles that we attempt to improve for a general audience. No amount of shouting at us is going to change the fact that there are few of us and so many articles. Moreover, a discussion that begins on the premise that all of our mathematics articles are inaccessible, and that project members don't care, can be quite frustrating to the actual project members who, by and large, do care about such things, and are already quite well aware of the issue. Secondly, many of us (yourself included) believe that it is better to have an article on a mathematics topic than to be silent on that topic, even if that article is pitched primarily at research mathematicians. A perhaps unfortunate result of this point of view though is that we do have many mathematics articles that are pitched at too high a level. But we also have many times more mathematics articles then there are physics articles. Our coverage of mathematics is much more comprehensive than physics, and that seems to be a good thing. Sławomir Biały (talk) 13:39, 18 January 2011 (UTC)
I completely agree. In addition I don't really that MathWorld or PlanetMath are necessarily better or more accessible in most cases. MathWorld often simply does not cover many of the more abstract subjects, i.e. the "greater Acessibility" is often achieved by simply not covering the subject. On more basic subjects, WP articles are usually as accessible as those on MathWorld, but in addition often more comprehensive and detailed. PlanetMath has many articles being not particularly accessible at all and on average it is hardly easier than WP. Not mentioned so far was Springer's Encyclopaedia of Mathematics being probably the "most distinguished" of our online competitors and it is clearly less accessible (as their primary audience are professional mathematicians).--Kmhkmh (talk) 14:00, 18 January 2011 (UTC)
I'm not sure on what you base that there are many times more mathematics articles, than physics articles. At best there is a factor of 2 more mathematics articles than physics articles (approx. 25,000 vs. 12,500). However, most of those are stubs, if you only count articles rated beyond the stub level, than there are more physics articles than mathematics articles (approx. 8,500 vs. 6,000). In all, I would say that the number of physics and mathematics articles are of the same order of magnitude.
I'm not sure what this says about either of the projects. WP physics, has it own set of problems (such as a much higher crackpot-to-expert ratio) and has its own set of almost completely unreadable articles. The general problem is that writing accessible articles about inherently technical articles is a lot of work, especially within the bounds of Wikipedia policy (especially WP:V, particularly WP:OR and WP:SYNTH). It is much easier to write technical articles at the same level of technicality as most of the sources used, and as a result a lot of articles that are written on these subjects are hard to read without a lot of background knowledge. This is still better than having no articles at all, in fact, having technically complete and correct articles is necessary as a first step for making them accessible.TimothyRias (talk) 14:56, 18 January 2011 (UTC)
I was looking at List of physics articles under the impression that it was maintained in a manner similar to our List of mathematics articles. But it's now clear that this is not the case. Consider me rebuked ;-) Sławomir Biały (talk) 15:07, 18 January 2011 (UTC)
Exterior algebra is one of the best math articles in wikipedia, thanks largely to the efforts of "S. Rabbit" in the past, and more recently other editors including Biały. Tkuvho (talk) 13:46, 18 January 2011 (UTC)
Really? Then why does it contain zero sentences that a non-expert can understand? Why doesn't it begin with some very basic sentence, like "Exterior algebra is a complex type of linear algebra used for areas and volumes, rather than lines" (assuming that I've made any sense at all out of the article, which I honestly doubt)?
Does your definition of "best math article" include only a calculation of the benefit to experts, with no thought to the need to make technical articles accessible? WhatamIdoing (talk) 16:40, 19 January 2011 (UTC)
The page exterior algebra typifies what I wrote about the hierarchical structure of mathematics. Just as a reader will not understand vector spaces until he is thoroughly familiar with examples such as Euclidean spaces, spaces of polynomials, etc., so also exterior algebra presupposes thorough familiarity with determinants and rank. You are correct to point out that the lead does not make this clear. I made a note to that effect. Tkuvho (talk) 17:05, 19 January 2011 (UTC)
Your change is not helpful. Telling people "we don't expect you to understand any of this unless you've spent years studying these other subjects" does not solve the problem.
Valid solutions give the non-expert reader at least an idea of what the subject is about. Non-experts don't need to understand every detail, but they should leave the first paragraph with a basic idea of what the subject is. Saying "I don't expect mere mortals like you to understand anything on this page" is not giving the reader a basic idea of exterior algebra.
To put it another way: I can explain basic algebra equations to a child who knows how to count, but not how to add or multiply. Surely all you smart people can figure out how to tell people who have studied far more mathematics than the typical four year old what exterior algebra is—unless, of course, you're more interested in showing off how "smart" you are than in writing an encyclopedia. WhatamIdoing (talk) 18:22, 19 January 2011 (UTC)
And we have figured out how to explain it to people with a basic background in college mathematics. The first paragraph of that article takes it down pretty much as simply as it's going to go. There is already a substantial introductory section explaining the connection to vector calculus. If this isn't good enough, then I don't see what the target audience could possible be. Four year olds? Seriously? Sławomir Biały (talk) 18:45, 19 January 2011 (UTC)
Your theory: "we have figured out how to explain it to people with a basic background in college mathematics."
My data: I am one of those "people with a basic background in college mathematics". I don't understand the article, or even the first paragraph.
If your audience is "people with a basic background in college mathematics" (a perfectly reasonable target, IMO) then you are not reaching your audience. WhatamIdoing (talk) 19:47, 19 January 2011 (UTC)
Well, I'm sorry that your education apparently omitted important topics like the cross product, areas and volumes (calculus) and rank and linear independence (linear algebra). It is not unreasonable to expect readers of this article to have a solid foundation in these ideas and there are constraints on what can be covered in the lead. I think we've done the best we can, based on experience teaching this subject to math/physics/engineering students. If there is a roadmap to writing a better lead for this article, I would happily look it over. But I haven't seen better. If my best isn't "good enough" then I might as well leave Wilipedia. Obviously my continuations are neither necessary nor appreciated. Sławomir Biały (talk) 21:37, 19 January 2011 (UTC)
A few comments here. Wikipedia incorporates elements of general and specialized encyclopedias (pillar one), so there is nothing wrong with adding advanced content. In this regard I think it is fair to say that the current state of the article mentioned targets more an undergrad student – even though it should be possible to understand the first paragraph with background in college mathematics. The question that comes to mind is how much does it make sense to "dumb down" an advanced topic? I can imagine the Motivating examples section to be simplified by being more informal, avoiding mention of undergrad topics like a basis, and so on, but what does it give? Still, you will require undergrad math knowledge to apprehend its usage. Just a question... (Besides, thanks to all the contributors for this extensive survey on the subject.) Nageh (talk) 22:38, 19 January 2011 (UTC)
(e/c) I think you underestimate the difficulty of explaining these advanced topics! I read pop math books from time to time, and they sometimes have ingenious ways of explaining a small part of modern mathematics to a high-school level audience. But most people, including Wikipedia editors, lack the ability to navigate so many levels, and many topics simply can't be explained that way at all. Even the authors of those books spend long periods trying different approaches to simplify the exposition; the average Wikipedia editor isn't willing (if indeed able) to spend 20 months pondering a single article as an author would with a book.
You may be one of the special people with this gift, in which case I encourage you to use it! But in the large majority of math articles it is the difficulty of explaining it rather than a failing on the part of the editors. (There are exceptions -- for a long time, and to some extent at present, wheel sieve was needlessly complex, to give but one example.)
I very much support the quest to make articles approachable for a wide audience -- but truly, there is 'no royal road'.
CRGreathouse (t | c) 19:00, 19 January 2011 (UTC)
Yes, I know that it's hard. IMO it is actually the hardest topic area in all of Wikipedia. The fact that it's hard does not change the fact that it needs to be done. These responses of "you're just too ignorant to understand anything at all about this subject" also don't solve the problem. WhatamIdoing (talk) 19:47, 19 January 2011 (UTC)
I have added substantially to the lead of the exterior algebra article. So much that now I think we are really breaking WP:LEAD. Is this the sort of thing you had in mind? Sławomir Biały (talk) 00:36, 20 January 2011 (UTC)

I can understand why people think it makes sense to compare physics and mathematics, but in reality it can only lead to false comparisons. The basic language of physics involves electrons, atoms, forces, time, energy, etc. In other words, (for the most part) it involves concepts that are taught to high school students. Other than that, the term "quantum" is an element of pop culture, and the concepts of Lagrangian and Hamiltonian are a step away from energy. Hell, kids even use the term "force field"; not totally accurately mind you, but still. The basic language of mathematics involves functions, topological spaces, groups, invariants, manifolds, graphs, rings, vector spaces, R-modules, categories, etc. While some of these are introduced at a high school or undergraduate, many of them are graduate topics. This makes it inherently more difficult to provide down-to-earth explanations on many wiki math articles. Take for example one of the biggest mathematical proofs of the recent past: Wiles' proof of Fermat. Luckily, you can fairly easily say a bunch of things about Fermat's Last Theorem; however, you'd be hard pressed to give a down-to-earth explanation of what the modularity theorem even says. Anyway, that's a bit of my rant. RobHar (talk) 16:02, 18 January 2011 (UTC)

Greetings Kevin, You have made an excellent observation and contribution to the discussion for this group. I have read your user page, and I am impressed by the time and thought you have put into NPOV. Please take a look at User:Gregbard/Mathematosis which is content that members of this group actively suppressed, and was moved from Wikipedia:MMSS to user space. It is no surprise to me that you have appropriately brought this important issue to the attention of the proper community, and have gotten a negative response from several of them. The prevailing attitude is represented by CBM (who is a wonderful and reasonable editor to discuss things with, however is still guilty of having this attitude that it isn't important at all for non-mathematicians to be able to understand mathematics articles in Wikipedia --a position he has stated in this discussion). Most of the active members couldn't care less if articles are only intelligible by themselves and their mathematician buddies. They are territorial and hostile to any interdisciplinary treatment of topics which might lend a great deal of clarity to non-mathematicians. As a note to the group, this poster Kevin has made a good faith report to this group for a need for improvement which the group has heretofore failed to achieve. His observation is valuable, as criticism is how we improve. Do not take this opportunity to dismiss him. Put away your arrogance, and adopt the humble position that he is speaking to an valid issue on behalf of the reading audience. Show some respect.Greg Bard (talk) 21:17, 18 January 2011 (UTC)

I think people should note that there was "no royal road to mathematics" when Alexander the Great asked for one; and there was considerably less mathematics in his day. While it is clearly the case that exposition of mathematical topics can be improved in some ways, those who insist that advanced topics can in some sense be made less advanced by cosmetic changes are simply barking up the wrong tree. Charles Matthews (talk) 22:09, 18 January 2011 (UTC)
Charles, consistent with your Alexander quote, an interdisciplinary treatment is the solution. In many cases, especially in the logic department, the solution is to provide the contemporary account given by analytic philosophers of mathematics. The entire project of analytic philosophy is clarification. When members of the group here are hostile to incorporating this kind of scholarship because they "don't see the need" or think it is "POV pushing" or simply disagree that it helps to clarify, with respect, they really are just demonstrating their own ignorance.Greg Bard (talk) 00:55, 19 January 2011 (UTC)
rofl CRGreathouse (t | c) 01:05, 19 January 2011 (UTC)
[23], nuff said Dmcq (talk) 12:12, 19 January 2011 (UTC)

I'm still awaiting outside input at exterior algebra. In light of some of the comments made here, I have completely rewritten the lead of the article. However, since the issues were never clearly identified (beyond a general lack of understanding), it is difficult to determine if I have hit the right mark. It does seem at the very least that those complaining loudly about its original inaccessibility should offer there feedback on the revision. Sławomir Biały (talk) 15:30, 20 January 2011 (UTC)

Being that I have a PhD in math, I seem to have to recuse myself from commenting on the accessibility of what you've written, I will therefore comment on the other side of the issue. Maybe first off, the first sentence is supposed to contain the word "Exterior algebra", otherwise perhaps this article should be moved to "Exterior product". Of course, starting this article with two paragraphs on exterior products is, I presume, simply trying to make the article accessible without being "allowed" to simply use a wikilink to "Exterior product" (which I've always thought should be its own article, I rarely use the exterior algebra, but often use various exterior products). Secondly, I realize that providing an overview of a subject will require hand-waving and white lies, but I generally look for a way to use language that gets across the same point, but technically manages to avoid lying. What I'm talking about is the current repeated use of the term "geometric space". As a mathematician, I read this, naturally, as "Euclidean space" (or "inner product space"), but the inner product is completely unneccessary for defining the exterior product. I think this could lead to confusion for someone who has the background/mathematical maturity to read this article, but doesn't yet know its contents. Perhaps using the word "Euclidean vector" instead of vector, and initially mentioning that the exterior product can be defined on any abstract vector space. I'm leaving these comments here because I think that they hint at some of the counterpoint issues in the current talk of accessibility. RobHar (talk) 15:58, 20 January 2011 (UTC)
I have added a link to vector space, since that is what the more sophisticated readers should have in mind. It's true that we also assume a Euclidean structure in this paragraph of the lead, but I have recently added a footnote that hopefully clarifies that as well. Sławomir Biały (talk) 16:13, 20 January 2011 (UTC)
Yup, the footnote works well. RobHar (talk) 16:24, 20 January 2011 (UTC)


I have been inspired by the above discussion to start an FAQ. It's currently visible at the top of this page. Anyone who wants to edit it is free to do so; it's at Wikipedia talk:WikiProject Mathematics/FAQ. Ozob (talk) 01:35, 18 January 2011 (UTC)

noticed the new FAQ. awesome. thanks, Ozob. well written. Kevin Baastalk 01:37, 18 January 2011 (UTC)
Well done Ozob. Probably something we've needed for a long time. Paul August 13:53, 18 January 2011 (UTC)
Great job. Will save a lot of ink in the long run, too. Tkuvho (talk) 14:02, 18 January 2011 (UTC)

"Law and medicine"

The first answer in the FAQ likened the difficult of mathematics articles to those in "law and medicine". User:WhatamIdoing has recently visited WP:MED and WP:LAW attempting to get them to say that their concepts can be made accessible; see WT:MED#Advanced topics and WT:LAW#On making technical articles accessible. By and large the folks at WP:MED were of the opinion that most of their material could be explained to the layman, though to me they didn't sound particularly enthusiastic. WhatamIdoing Anthonyhcole has used this as justification for removing "and medicine" from the FAQ answer, and I am sure he hopes to do the same for "law". I've replaced "medicine" with "medical science" since that seems to me to be closer to the actual consensus in that thread.

I'm starting this thread in the interest of centralizing discussion. I'll shortly be posting to the Law and Medicine WikiProjects directing them here. Ozob (talk) 12:37, 20 January 2011 (UTC)

Whatamidoing did not edit the FAQ. [24] --Anthonyhcole (talk) 13:34, 20 January 2011 (UTC)
My apologies; I stand corrected. Ozob (talk) 21:58, 20 January 2011 (UTC)

Praise for the new lead at Exterior algebra

I am totally impressed with the huge improvements to the lead at Exterior algebra. I finally understand what the subject is, and why anyone should care about it. (It's the biggest tool for certain purposes! It provides complete, precise, unambiguous definitions instead of just vague descriptions! It's sometimes convenient! It has desirable properties! It's useful! It's compatible with some other things!)

In terms of practical feedback:

The subject is advanced so the material is naturally dense, and I read the lead slowly, trying to reactivate some rather rusty neurons. The occasional parenthetical comment (e.g., the degrees add (like multiplication of polynomials)) helped me connect the current subject to some basic but apparently rusty concepts (going from "The degrees add?!" to "Oh, he means the degrees add! How could I have forgotten!"). It's still not going to be accessible to someone at the pre-algebra level and that's okay. I think it's going to be accessible to someone who has studied vectors past the introduction-to-physics level.

The lead makes judicious use of occasional "needless verbosity" as a way of introducing unfamiliar terms. For example, it says The exterior product of two vectors u and v, denoted by u ∧ v, lives in a space called the exterior square, rather than The exterior product of two vectors u and v, denoted by u ∧ v, lives in the exterior square. The difference from the perspective of the non-expert is that the chosen construction says "Now you know what we call this bit, and that's all you need to know about that for now" rather than "Here's another bit of jargon to prove that you don't know what we're talking about!" I found this so effective that I plan to adopt this strategy for other technical subjects.

The newly added image helped me check my understanding of the first paragraph.

In the end, I felt like I understood the main point of every single sentence, at least to a first approximation—well enough, in fact, to confidently identify and fix a minor typo that the spilling chucker missed, without wondering if perhaps this was some strange new mathematical concept.

I'm enormously happy about the new third paragraph, which contains most of the "What's it useful for" and "What field is it studied in" answers. (The short answers to those two questions are "Lots of things" and "Several", and as a result, I know why this article is a high priority on this project's WP:1.0 assessments.)

This is such a wonderful bit of work. Thank you to all who helped, directly and indirectly. WhatamIdoing (talk) 18:24, 21 January 2011 (UTC)

I think that new lede has some good material, but it is far too verbose for the lede section of an article. — Carl (CBM · talk) 20:20, 21 January 2011 (UTC)
I agree that it is long—three paragraphs of ten sentences each—but I don't think that it is too long. Instead, I think it is just about as long as necessary. Except for possibly the parenthetical description of differential forms, I'm not sure what could be cut without failing to identify the subject and its importance to the reader.
One reason that I think its length is appropriate is because it's really introducing two closely related subjects: Exterior algebra is also the article for Exterior product. So you've got ten sentences on each of two 'subjects', and ten sentences that apply more or less to both 'subjects'. WhatamIdoing (talk) 21:29, 21 January 2011 (UTC)

Ono partition proof

Ono et. al. have recently published a paper which is getting a lot of hype. If someone can work on Partition (number theory) in preparation for that would probably be good. The paper deals with congruences and a new closed-form formula (I've only skimmed it so far); we should, in particular, work on Partition (number theory)#Congruences if at all possible. At the moment that section directly contradicts itself.

CRGreathouse (t | c) 00:15, 22 January 2011 (UTC)

A picture is worth 1,000 words

Although I did Maths up to it being a subsidiary subject at first-year university level, I've forgotten most of it, although I do like to try to get a vague grasp of concepts as I come across them (see, for example, the above discussion about Lyapunov vectors). So I can heartily commend and congratulate that article for including a diagram which, more than thousands of words could do, gives the outside reader a rough idea of what's going on. Excellent. Any chance of a few more articles doing likewise? If diagrams are tricky, then use a real world example if possible: "Imagine this scene 'X' ... aspect 'Y' is described by mathematical concept 'Z'." (I realise this really may not be possible in various cases, but I'm sure it must be in some, as per Lyapunov vectors.) In short, could articles, where possible, attempt to teach a non-mathematician? Thanks. Feline Hymnic (talk) 09:52, 8 January 2011 (UTC)

Mathematics is abstract by nature and it is often difficult to come up with a diagram which illustrates a concepts in any meaningful way. But I'm sure there are quite a few math articles where a diagram would very helpful, and others where the existing diagram(s) could be improved. I believe Template:Reqdiagram can be added to an article to request a diagram and add it to the corresponding category, but I don't know if we have a way of sorting out just the math articles from the list. Wikipedia:WikiProject Mathematics/Graphics has some links to the Wikipedia:Requested pictures page but the indicated sections don't seem to exist.--RDBury (talk) 23:32, 8 January 2011 (UTC)
There is a list here for future reference. It's mainly for photos but diagrams seem to be included as well.--RDBury (talk) 18:09, 9 January 2011 (UTC)
Someone should split that list into mathematicians and mathematics articles. I'm sure that should be easy for the bot to do. Sławomir Biały (talk) 20:46, 9 January 2011 (UTC)

There are places where diagrams would help. But even when you can sketch a diagram in a few seconds on the back of an envelope, it may take two hours, or eight hours, to create something that can be uploaded. Michael Hardy (talk) 16:57, 9 January 2011 (UTC)

In many cases, I think that even a less than perfect diagram is better than none at all. And overall I heartily agree that many of our articles could use more illustrations. A useful first task, per above, would be to organize a list of articles needing images, although realistically the list should be fairly long. Sławomir Biały (talk) 20:46, 9 January 2011 (UTC)
I agree. In drafts of papers it's routine to sketch a diagram on paper and scan it in as a placeholder. Similarly, once in a computer science article I encountered a diagram that was apparently drawn by mouse using MS Paint. These lo-fi diagrams not only are better than no diagram, but also strongly encourage the production of a higher-quality one. Dcoetzee 22:50, 9 January 2011 (UTC)

Although I've tended to emphasise pictures, diagrams, etc. to help the outsider get a finger-hold on a concept, another really valuable way to do this is a "motivating example". For instance, many years ago I couldn't see any point to the vector cross product. "Why bother?", I thought. "Completely perpendicular to the usual vector plane? Crazy!", I thought. But in another isolated compartment of my poor little brain was already squirrelled away the right-hand rule for electro-magnetic induction. Then in one physics lesson about electromagnetism, the lecturer said, almost as a throw-away, "...and we can express this mathematically as a vector-cross product." And the light went on: "Yes, at last, I get it!". So, if reasonably possible, could articles have some sort of "motivating example" near the top? Feline Hymnic (talk) 12:38, 22 January 2011 (UTC)

Here's some more support for the principle that putting examples early in the article is good pedagogy. —David Eppstein (talk) 17:21, 22 January 2011 (UTC)
I recommend GeoGebra as an excellent package for creating mathematical graphics. It's not so good with colours, but you can export any pic you generate as a PNG and use Paint or something to colour areas in. --Matt Westwood 12:54, 22 January 2011 (UTC)
PNG and more generally bitmap graphics are inappropriate for most mathematical illustrations. We should be using vector formats such as SVG. —David Eppstein (talk) 17:22, 22 January 2011 (UTC)

Drive-by reverts at Midy's

Midy's theorem is being enriched by unsourced material. Tkuvho (talk) 04:05, 19 January 2011 (UTC)

The article said:
If the period of the decimal representation of a/p is 2n, so that
Does "so that" make sense? I.e. if the denominator is a prime other than 2 or 5 and the numerator is less than the denominator, is it necessary that the repetend begins immediately after the decimal point? If so, I think the article should mention that, and so should the one titled repeating decimal.
For now I've changed it so that it says this:
If the period of the decimal representation of a/p is 2n, and
Michael Hardy (talk) 22:58, 19 January 2011 (UTC)
You should be able to get the original WLOG. CRGreathouse (t | c) 20:47, 20 January 2011 (UTC)
Yes, it is necessary that the repetition begins immediately after the decimal point. If 0<a<p and p is prime (but not a factor of the base), then remainder of the long division of a by p after ai is congruent mod p to a×10i. These remainders form a coset of a subgroup of the multiplicative group of Zp. Or you could just read the proof in the article carefully to see it.
Actually, this is covered in a more general way at Repeating decimal#Reciprocals of integers not co-prime to 10. Although that is only talking about fractions whose numerator is 1, it also applies to other numerators co-prime to the denominator. JRSpriggs (talk) 06:07, 21 January 2011 (UTC)
Please see Talk:Repeating decimal#Why does repetition begins where it does?. JRSpriggs (talk) 09:05, 22 January 2011 (UTC)

Hadamard's maximal determinant problem

Hadamard's maximal determinant problem is a quasi-orphan (in the article space, one "article" and one list link to it (and I shouldn't have to tell you which list)). Try to figure out which other articles should link to it, and add the links. Michael Hardy (talk) 18:14, 22 January 2011 (UTC)

Tangent half-angle formula

Tangent half-angle formula has long been a deficient article. It's not as bad as it was 30 minutes ago, but more work is needed.

The illustration would accompany a geometric proof fairly well, but it's badly titled, and also see my commented-out comment on it within the article.

I'm not sure the Weierstrass substitution should be mentioned other than very tersely. There's a main-article link for that. Michael Hardy (talk) 02:45, 23 January 2011 (UTC)

Mathematical economics: Shapley-Folkman, Chichilnisky, & Mas-Colell

In the last 3 days, User:David Eppstein created articles on the mathematical economists Andreu Mas-Colell and Graciela Chichilnisky (yesterday).

Chichilnisky's continuous social choice theory may interest topologists, especially; her work on international trade, development, and environmental economics has received international attention; further, she has received national attention in the USA because of a (now settled) sex-discrimination law-suit.

Also, another article started by David, the Shapley-Folkman lemma, received "Good Article" status today, thanks to the reviewing of User:Jakob.scholbach, who guided the needed revisions. Further editing, especially copy-editing, would be appreciated.

Best regards, Kiefer.Wolfowitz (talk) 22:54, 19 January 2011 (UTC)

Did you know? for Chichilnisky, Mas-Colell, and Henry Mann

There is a new article on the algebraic/additive number theorist Henry Mann, who was also a statistician.

I nominated the 3 mathematical articles for DYK, and so I encourage mathematical-project editors to review the DYK facts. Thanks, Kiefer.Wolfowitz (talk) 02:18, 24 January 2011 (UTC)

What are the DYK facts? Please provide a link to where the proposed "facts" are? JRSpriggs (talk) 04:24, 24 January 2011 (UTC)
They're on T:TDYK while they await approval. —David Eppstein (talk) 04:56, 24 January 2011 (UTC)


A user at Talk:Exterior algebra asked me to define what I mean by "Bourbakism". As this is an important issue I am starting a thread here. As pertaining to the style of the pages here, particularly the ledes, what I am referring to is the idea that the latest fad in the foundations of mathematics is also the foundation of human thought and therefore should be the foundation of education. In the sixties, set theory was fashionable as a foundation. This foundationalist mentality therefore led to the New Math debacle in education. Concepts such as "naturality", "universal constructions", "equivalence of categories" are certainly appropriate on some math pages, but not most. Thus, understanding the naturality and universality of the exterior algebra is important in its applications in de Rham theory and building the exterior differential complex, etc. However, such concepts are basically a Bourbakist infestation when it comes to explaining basic concepts such as exterior algebra, and should be relegated to the last section of the page. I appreciate the effort that went into the upgrading of the page exterior algebra recently, but at the same time misguided educational principles should be checked. The elaboration of the "categorical" material has been accompanied by the deletion of material on simple-minded topics such as rank, minor, and cross product which can serve to connect the topic to the reader's previous experience. However, if you are Bourbakist, connecting to previous experience counts little when one is dealing with alleged foundations of human thought. Tkuvho (talk) 10:00, 23 January 2011 (UTC)

Just as an aside, Bourbaki seminar publications did not use categorial approach to mathematical structures and instead developed them using sets with additional structure. This approach is still widely used today, and I like it. Now, as I said in the talk page on Exterior algebra, the concept of the largest algebra satisfying this or that property is intuitive, and no category theory was explicitly invoked. I think you're overreacting. P.S.: Set theory is the foundation of modern math, not just 'a fad'. — Kallikanzaridtalk 10:17, 23 January 2011 (UTC)

The discussion at Talk:Exterior algebra is quickly becoming tiresome and unproductive. A nutshell version is that Tkuvho feels that the lead of a mathematics article should not even attempt to summarize the more advanced parts of the article, because of accessibility concerns. Some outside comment is obviously needed. Sławomir Biały (talk) 14:07, 23 January 2011 (UTC)

The lead still contains some errors, partly due to the overemphasis on "universal constructions", as I pointed out at the said talk page. Outside comment will be welcome. Tkuvho (talk) 14:11, 23 January 2011 (UTC)
I can't see any, can you point them out? — Kallikanzaridtalk 15:08, 23 January 2011 (UTC)
See here. You are the one who acknowledged the error in an earlier edit on this (WPM) page! Tkuvho (talk) 15:13, 23 January 2011 (UTC)
It's just not relevant to what we're discussing. If you want, you can consider Euclidean space where vector fields can be (and are being) safely introduced as mappings to . The concept of vector and covector fields is just not as advanced as you picture it to be, and Slawomir correctly identified that even on an arbitrary manifolds such fields form a module so you can't even argue that the generalization from Euclidean space to manifolds is not straight-forward—it is! — Kallikanzaridtalk 16:22, 23 January 2011 (UTC)

Considering that Bourbaki was founded in the 1930s, calling it a recent fad is a bit odd. And trying to tie in Bourbaki's stated wish to write an encyclopedic reference for contemporary mathematicians with the New Math is something of a slur; if you wish for more context read the introduction to Dieudonné's Infinitesimal Calculus; it was much more of a question of getting the French university examiners to consider whether undergraduate teaching should have some relevance to research topics. The excesses of American educators, post-Sputnik, are really only vaguely related. It is obviously the case that our treatments of graduate-level topics should reflect graduate-level textbooks. Those are a mixed bunch, but the "formalist" treatments will be in evidence in certain areas of higher algebraic content, and it is perfectly fine that our articles should reflect that to some extent. My impression is that the anti-algorithmic and "no pictures" prejudices of Bourbaki are now pretty much obsolete, so that heuristics on how you compute with the exterior algebra (say), and some geometrical interpretations, are appropriate. Also some history gives a chance to speak to why ideas were introduced in the first place, which usually helps. Charles Matthews (talk) 15:47, 23 January 2011 (UTC)

But in this case, the charge of Bourbakism can only refer to a parenthetical mention of the universal construction. The vociferous criticism of one particular user seems to be totally out of proportion to what actually appears in the text. Sławomir Biały (talk) 16:05, 23 January 2011 (UTC)

Certainly the basic principle is that the choice of content should not be anyone's personal taste, but a reflection of a mainstream view. Charles Matthews (talk) 17:34, 23 January 2011 (UTC)

The last I heard the mainstream view was that college juniors are unfamiliar with either "functors" or "universal constructions". You may want to consult Talk:Exterior algebra where it just turned out that college juniors are intimately familiar with the idea of an unfree module. Tkuvho (talk) 17:41, 23 January 2011 (UTC)
Point me to the sentence in the lede that relies on that — Kallikanzaridtalk 17:51, 23 January 2011 (UTC)
(ec) Comments like this and your recent edit to the new FAQ make me wonder if maybe WP:IDIDNTHEARTHAT and WP:POINT are getting to be increasingly relevant. Many of your comments suggest that you have not even read the lead (eg equivalence of categories, natural transformations, module coefficients—none of which even appear in the lead), and your comments here and elsewhere have demonstrated a propensity to read what others write very selectively as well. None of this seems to be headed in a constructive direction, largely because it doesn't seem to be focused on the actual text. Instead it seems to be about being "right" about some fine points of rigor. Sławomir Biały (talk) 17:54, 23 January 2011 (UTC)
I am perfectly prepared to stop this discussion if you find it aggravating. Tkuvho (talk) 18:06, 23 January 2011 (UTC)
It's not that it's aggravating, it's that it doesn't seem to be about the same article. Sławomir Biały (talk) 23:04, 23 January 2011 (UTC)

My one cent

I agree with posts I have seen elsewhere. I think the lead for Exterior algebra generally looks great. Thank you to all the editors who have worked on that text! ---My Core Competency is Competency (talk) 18:30, 23 January 2011 (UTC)

More eyes needed?

User:Gauravmisra del mentioned on his userpage last month that he was having trouble with the wiki-syntax necessary to add his Remarkable Discovery to the article on subtraction without borrowing. He subsequently went ahead and added it (I guess he figured it out?), so that's fine, I guess.

Problem is, I'm concerned about his description of this as a Discovery, which evokes Original Research. But this really isn't my field. I'm sure I could follow his step-by-step instructions if I tried, but I wouldn't be able to recognize whether this is something new and original or old and familiar (and his mention of the psychological side effects of ordinary subtraction seem... unusual, to say the least). Anyone care to have a look? DS (talk) 15:12, 24 January 2011 (UTC)

What's the template for speedy deletion of amateur's self-promotion? :) P.S.: The guy is probably a troll. But please do read, it will make your day! :D — Kallikanzaridtalk 15:46, 24 January 2011 (UTC)
My Google search for subtraction without borrowing reported 87,200 results.
Wavelength (talk) 17:10, 24 January 2011 (UTC)
I put quotes round the phrase and got about 17000. I looked at the first and it said "skills include subtracting without borrowing, subtracting with borrowing", so it is obvious they mean a progression in skills where they first set problems where borrowing wasn't required. I guess most are like that. Anyway we should not be the first publishers of remarkable ideas. Dmcq (talk) 20:24, 24 January 2011 (UTC)
It is especially true because this 'remarkable idea' is more than 3000 years too late to be truly remarkable. — Kallikanzaridtalk 20:57, 24 January 2011 (UTC)
So it can't be related to this bit of New Math? :) Dmcq (talk) 21:25, 24 January 2011 (UTC)
I'm sorry that you Americans were so much traumatized by misguided attempts to rival our sheer awesomeness 8) — Kallikanzaridtalk 21:56, 24 January 2011 (UTC)
So... who wants to AfD this? Unless someone thinks it would survive a prod... I don't think it qualifies for a speedy. CRGreathouse (t | c) 21:05, 24 January 2011 (UTC)
By all means, proceed :) — Kallikanzaridtalk 21:56, 24 January 2011 (UTC)
Perhaps redirect to Method of complements? --agr (talk) 22:16, 24 January 2011 (UTC)

Lede of Hermitian manifold: eyes needed

IMO the sentence about the connection almost complex structure has two errors:

  1. As pointed out in the talk page, almost complex structure preserves the metric, not the other way around,
  2. More importantly, this is almost Hermitian manifold, for Hermitian manifold you need complex structure, not just almost complex one.

I'm writing here because I don't think many people are watching that page :) — Kallikanzaridtalk 18:49, 24 January 2011 (UTC)

I changed the lede, please check for the correctness — Kallikanzaridtalk 18:35, 25 January 2011 (UTC)

Prime number

Anyone willing to join me in making this article Good? I think prime numbers [c,sh]ould be a showpiece maths article, ranging from most elementary math's to jungles of unsolved conjectures and recent top-notch work. Everybody, please inscribe yourself here! Jakob.scholbach (talk) 23:17, 26 January 2011 (UTC)

Australian Mathematical Society - a reliable source?

Is the Australian Mathematical Society ranking of mathematics journals a reliable source for list of mathematics journals? Opinions on that question are welcome at Talk:List_of_mathematics_journals#AustMS_journal_rankings. — Carl (CBM · talk) 04:49, 28 January 2011 (UTC)

Feb 2011

A concrete proposal to help the beginners

My suggestion is to adopt a guideline for math pages (particularly the more advanced ones) that they should include a specific pointer to the more elementary topics that need to be mastered in order to understand the more advanced page. The pointer should consist not merely in a mention of a page imbedded in a clause in a long sentence, but a specific mention that the linked page is more accessible. Here is an example. Riemannian manifolds and their curvature cannot even begin to be approached until the student has mastered the theorema egregium of Gauss and the idea that Gaussian curvature is an intrinsic invariant. Pages such as Riemannian manifold should make it clear that the reader has to understand surfaces first. A similar example: I believe the reason the contributor who expressed himself above cannot make any headway in exterior algebra is because the wedge product appears there in a completely "ex nihilo" fashion. By the time the article gets around to construct the exterior algebra in terms of the tensor algebra (!), we have already lost all beginners. The page exterior algebra is a great page, but it could be made more accessible to someone with basic background in linear algebra, but not much more. I tried to link it to more elementary pages in the spirit of my suggested guideline above, but encountered reverts on the grounds of being "unencyclopedic". We should adopt a guideline making it encyclopedic to try to help beginners. Tkuvho (talk) 22:09, 19 January 2011 (UTC)

I'm not completely opposed to this in principle (though the idea has never really gone over well in the past). But it seems to me that there are a lot of practical difficulties in getting it really right. Just to start with, I'm not sure I agree with your specific example — when I took a course in semi-Riemannian geometry, I had never studied the theorema egregium by that name, though I did know the concept more or less. I doubt that that theorem per se is a true prerequisite, though I'm not saying it wouldn't be helpful. I see this proposal as giving us new and exciting things to argue about in every article.
For difficult articles, the list of concepts to be mastered before a "beginner" can approach them is pretty intimidating. Is the idea to present, say, just a few immediately-more-general notions, with it being understood that you also need the sort of general familiarity with a whole range of concepts and techniques without which you wouldn't understand the immediate "prerequisites" either? --Trovatore (talk) 06:27, 20 January 2011 (UTC)

"The idea" is that a beginner who looks at, say, riemannian manifold, should not walk away baffled, intimidated, and non-plussed, having learned nothing. If we offer him some leads to lower-level articles, he will either look at those and learn something, or else say, OK, to understand Riemannian manifolds I need first to know what Gaussian curvature is. This is far less discouraging than walking away completely baffled, which seems to have been the experience of some of the beginners who expressed themselves above. Every college course has a list of prerequisites in the course catalog. I am not sure why some mild approximation in wiki should be viewed as such anathema. And I don't think this is "condescending" toward the beginner (see comment below), on the contrary, endless blather about "non-encyclopedic" is condescending. Tkuvho (talk) 14:00, 20 January 2011 (UTC)

Well, I agree with the reverts because I don't think your pointer was in quite the right place and expressed in quite the right way. At Chain rule#The chain rule in one dimension, there's a hatnote that says, For an explanation of notation used in this section, see Function composition. Placing the pointer separately from the main text warns the reader what he's getting into before he starts, and I think that's better style.
But I also wonder whether we should have that kind of message at all. I think a really good article wouldn't need a hatnote like that. I have some recollection that we've discussed this here before, but I can't remember what the outcome was. Ozob (talk) 00:14, 20 January 2011 (UTC)
If you go to the "Search Archives" box and enter "Prerequisites" (here, I've done it for you) some relevant discussions appear. --Trovatore (talk) 06:18, 20 January 2011 (UTC)
The hatnote may be a good idea. At any rate this sort of thing should be anchored in official guidelines because you will always have purists who come along and say this is unnecessary. A beginner's needs should be anchored in guidelines. As far as your remark concerning "really good articles", I agree in principle but we have very few of really great ones in the sense of being accessible to beginners. Certainly neither Riemannian manifold nor exterior algebra is at present, as I argued above. Should we wait for them magically to turn into "really great ones"? The users above were right to complain about them. Tkuvho (talk) 05:53, 20 January 2011 (UTC)

I think it is generally a bad idea to start of an article by saying: "you should know this, this, and that before attempting to read this." (Or any friendlier message with the same content.) It feels really condescending to me. Moreover, it encourages laziness on part of the editors, by just allowing them to put up some prerequisites and not push to obtain the uttermost accessibility that is possible for the subject. In particular, it encourages starting articles at a high entry level, instead of steadily increasing the difficulty level as the article proceeds. Another thing to keep in mind, is that there can exist vastly different roads to understanding a mathematical subject. A pattern I sometimes see in the thinking about accessibility of math pages on this project, is that it tends to focus on the path that a typical mathematics student would take in learning about the subject. This is not surprising since it is the path that many of contributors here followed/are following, but many users will actually have a different background, which often misses some of the mathematical foundations that a mathematics student would have, but might on the other hand might include a lot of hands experience of using similar structures. For example, students of theoretical physics will learn about Riemannian manifolds in a GR class without any solid knowledge Gaussian curvature or the theory of surfaces (that a mathematics student would have.) Similarly, when (even if) physics and engineering learn what a tensor of a vector bundle is, they usually have been working with examples of these structures for years. I think that a similar effect to providing a list of prerequisites, (without the possible condescending connotation) can be achieved by detailing in the lead what types of things a concept is generalizing and/or naming a few well-known (to people that do not already know about the subject) concrete examples. This typically are things that a reader should know about to understand the article. A reader that has never heard about any of these things, will generally get the clue that he has encountered an article for which he doesn't even properly understand the basic context. Although hopefully he will have a much better idea of the context then before.TimothyRias (talk) 13:29, 20 January 2011 (UTC)

As one of those reverting the change I should add my thoughts. Perhaps my overriding concern is that articles are about a particular topic, and so be written about that, in an encyclopaedic but accessible way. That means that comments about the article, even indirect ones such as "before reading this, read this", have no place in it. Far better to write the article in a clear, straightforward way to make it as accessible as possible to as wide an audience as possible.
That does not mean we don't help those who would be better off reading something else first. In fact we go to great lengths to support them. Through well-chosen wikilinks, through 'See also' links, through navigation boxes, templates and project pages we guide users to articles on related topics and more fundamental ones so they can find those most of use to them. We don't make assumptions about what they know, we show the connections between topics so readers can navigate to the ones they need. We also provide references that often are much more useful for learning from than a factual encyclopaedia article. Arguably we do more like this, and do it better, than any other encyclopaedia, in a way that doesn't interfere with writing the best encyclopaedia articles we can.--JohnBlackburnewordsdeeds 13:52, 20 January 2011 (UTC)
This discussion should not be about specific reverts but rather about a mild "prerequisite" guideline. If you feel strongly about exterior algebra we should focus on a more neutral example such as riemannian manifold, see my comment above. There is no way of making this accessible without copying a large part of differential geometry of surfaces into it. Either we provide gentle hints to the beginner, or we don't, and merely leave him baffled. Tkuvho (talk) 14:05, 20 January 2011 (UTC)
I've added an introduction section to Riemannian manifold which I hope should help. I think many of the complaints about math articles on Wikipedia can be addressed by improving the lede or adding a less technical introduction. However that should not preclude other, perhaps interim, steps, that suggest an article to read first. If we can have a { { main } } tag, why not an { { intro ] } tag that says something like For an introduction to this subject see. I'm often bothered by the adjective "encyclopedic" as used on Wikipedia, which seems to mean "helpful, but not too helpful" rather than its dictionary meaning.--agr (talk) 16:52, 20 January 2011 (UTC)
It's a problem with technical articles that the people who know enough about a subject to write about it intelligently tend to be more used to writing for their colleagues than for the general public. So many articles are filled with jargon that only someone who would already be familiar with the subject out be able to get past. (I just ran across this in a psychology article so the problem isn't restricted to mathematics.) On the other hand it's impossible to start from first principles on every article so a certain level of prior knowledge must be assumed. I don't like the idea of adding a specific prerequisites section because the introduction should be telling the reader that implicitly already. For example in math we tend to start article with a phrase like "In topology ...", which should tell the reader that if their not familiar with topology then they'll probably find the article rough going. In the example above, the article on Riemannian manifolds should have a sentence to the effect that it arose from the study and/or is a generalization of the idea of Gaussian curvature and the reader should get the idea that it would be a good idea to be familiar with the latter before getting into the details of of the former. Also, WP is meant to be a reference and not a textbook, so the task isn't to teach the subject from a clearly defined starting point anyway. I do think the general level of the target audience should be identified somewhere though, probably on the talk page. It may be tricky to do this for longer articles since some have advanced level information even the introduction in written at an elementary level. I think it would be helpful for future editors, once the article has taken shape as to content, to know for example that the introduction and history sections should be kept accessible to a general audience, the derivation should be understandable to someone with freshman calculus, and the rest of the article is at grad school or higher level.--RDBury (talk) 16:59, 20 January 2011 (UTC)
@RDBury: I like your proposal a lot. Note however that what you are proposing is much more radical than my proposal. I am merely proposing a mild introduction hatnote guideline, which only involves minor adjustments to existing articles (that, in my opinion, go a long way in helping beginners). If I understand your proposal for the introduction correctly, it would involve rewriting a large percentage of our articles, and would certainly require an official guideline to succeed. Just check the current lede at exterior algebra and tell me if it is "accessible to a general audience", which seems to be evolving in the opposite direction. Thus, a discussion of determinants and rank has just been deleted. What seems to have taken its place is a discussion of equivalence of categories and universal constructions, with the justification being that "we are constrained by a need to summarize the article in the lead, and a large part of that is dedicated to these issues". Is the lede supposed to be a scientific abstract of the article?
Tkuvho — my sense is that (i) you read RDBury as saying that all introduction sections should be kept accessible to a general audience but that (ii) he was really saying that there should be a way of recording the decision that a particular article has an introduction section that can be kept that accessible. Certainly there are plenty of topics (actually, the ones I'm most interested in writing about are all in this category) where the best we can hope for a general audience to take away from the article is not much more than "that's some complicated math thing". However if an article has been written with an accessible introduction, then clearly it can be, and RDBury was proposing (I think) that there should be some way to remember that. --Trovatore (talk) 06:16, 21 January 2011 (UTC)
(Just to be clear, I was speaking in generalities and not really looking at a specific article. To answer your question, no, imo abstracts belong in a journal article but not an encyclopedia article. Off the top of my head I'd say the introduction for the article like "exterior algebra" should be written for a junior or senior college math major.)--RDBury (talk) 05:19, 21 January 2011 (UTC)
Consensus in the past has been that the lead of the article should conform to WP:LEAD, meaning that it should be an overview of the article that is accessible as possible, but it should not leave out the harder bits just because those are impossible to describe for the layman. The lead needs to be a summary of the article for everyone—beginners, experts, and everyone in between. There has also been consensus in the past that a separate introductory section can be helpful for beginners. There is obviously confusion in this thread whether by "introductory section" you mean "lead" or actually "introductory section" in the sense that our WP:MSM uses. Could you please clarify? Sławomir Biały (talk) 12:35, 21 January 2011 (UTC)
I do think of lead section and introduction as the same thing, sorry if that caused confusion.--RDBury (talk) 15:08, 21 January 2011 (UTC)
Note that this does not have to conflict with making the lead more accessible than the main text. Being a summary, the text in the lead does not have to have the same amount of rigor as the main text. In many cases it would be OK to have a statement in the lead that is (from the perspective of a mathematician) slightly ambivalent, which is clarified with more mathematical rigor in the main text.TR 12:46, 21 January 2011 (UTC)
Agreed. Sławomir Biały (talk) 13:22, 21 January 2011 (UTC)
@agr: Thanks for sharing your thoughts on the adjective "encyclopedic". I wholeheartedly agree. I like your suggestion for an { { intro } } tag. If we can get a guideline approved in this direction, we would have an official basis for fighting off some of the "encyclopedic" browbeating. As far as I see that makes the two of us supporting the idea, though, with an additional "maybe" from Trovatore. Any ideas, fellow editors? Tkuvho (talk) 19:13, 20 January 2011 (UTC)
I don't think that RDBury's proposal is radical. I think it's similar to the existing official guideline at Wikipedia:Manual of Style (mathematics). Most of the articles that people are complaining about are currently in violation of this guideline. WhatamIdoing (talk) 21:04, 20 January 2011 (UTC)
The lede is currently dominated by a Bourbakist formalist attitude that has seriously degraded the quality of the article. The vague expostulations border on error, as when the lede confides that the exterior algebra construction can be generalized to more general vector spaces such as spaces of vector fields or differential forms. This may lead the reader to conclude that one is calculating the exterior algebra of the said infinite-dimensional vector space, which would be complete nonsense. I can't fight this alone, though. Tkuvho (talk) 21:28, 20 January 2011 (UTC)
The lede of exterior algebra is not at all like Bourbaki. I disagree with your other claim as well, what exactly is your problem with saying the exterior algebra construction can be generalized to vector fields? RobHar (talk) 06:08, 21 January 2011 (UTC)
It can, it's just that these are not vector spaces, but sections of respective bundles, so construction is done pointwise, and then we take sections of the resulting bundle. — Kallikanzaridtalk 08:29, 21 January 2011 (UTC)
(@Tkuvho) The lead is supposed to summarize the most important points of the article. Since the article seems to be largely sourced to Bourbaki, naturally the lead is going to summarize some "Bourbakist" material. By and large, it's actually the more accessible content that tends to violate WP:LEAD, and there is always a tension between the demands of making a technical article accessible and conforming to WP:LEAD. In the case of the exterior algebra, two paragraphs of introductory material of the lead is wildly out of proportion to its representation in the text. Sławomir Biały (talk) 12:38, 21 January 2011 (UTC)
(ui)I'm not sure that appeals to WP:LEAD are valid since we are, in effect, discussing the possibility of changing it, at least for math articles. (There seems to a couple threads here at once, actually.) I think the rationale for WP:LEAD are: a) WP is a reference work so people from a wide range of backgrounds may come to an article. b) Many people reading an article will not read beyond the lead section, some won't go beyond the first sentence. c) An article should provide benefit to as wide a range of possible readers as possible, from those who just want a vague idea what the subject is to those who are already familiar with it and want to fill in some details in their understanding. My conclusion is that the lead section primarily serves the lower end of that spectrum. It the private sector it's called an "elevator speech", or "How would you describe the your job (or the subject of an article) to someone you met randomly in an elevator before they get off at the next stop?" The higher end of the spectrum are served by the latter parts of the article and will probably blow past the lead section anyway. This is a big reason WP writing is so different from textbook writing, in a textbook you can assume all readers are starting at the same point and are committed (with their tuition money) to see it though to the end. Yes, you do want to include the important aspects of the subject since even a casual reader may want to know why someone might be interested in this strange new idea they've come across. But this should be written with the casual reader in mind for the lead section. My favorite example of how this should be done (perhaps because I put a lot of work into the article) is W:Catenary. Everything above the "Mathematical description" section should be accessible to a high school student and there is even eye candy so no one falls asleep.--RDBury (talk) 16:21, 21 January 2011 (UTC)
Remark, changing WP:LEAD is pretty much out of the question. It is a wikipedia wide guideline, changing it would require consensus very much beyond this project. Since it is wikipedia wide guideline, it will apply to mathematics articles no matter what additional guidelines we would impose. The most we could do is provide a guideline, of how leads in maths article could best realize the requirements of WP:LEAD. Writing such a guideline, that collects various "best practices" of how to deal with the difficulties of satisfying the various aspects of WP:LEAD in articles about abstract mathematical subjects, might actually be a good idea.TR 16:41, 21 January 2011 (UTC)
There should not be any situation where text X is the best article on a given subject but WP:LEAD forces us to choose an inferior text Y. If there is in a rare instance, WP:LEAD can be ignored--it's just a guideline. If problems arise regularly and there is project consensus on what should be done differently, WP:LEAD can certainly be supplemented by a math specific style guide or altered itself if need be. The guidelines are there to help editors, not get in their way.--agr (talk) 22:33, 22 January 2011 (UTC)
A guide of best practices seems like a good start in any event. There is clearly a lot of confusion, not just about how WP:LEAD can help improve our articles, but indeed what WP:LEAD actually demands. I find our own WP:MSM not to be very helpful in clarifying what the ideal lead of a mathematics article should look like. In particular, it confuses an introductory section for the lead, whereas I think one of our current best practices is that these are generally different things. Since the time that was written, many of the other guidelines have changed to reflect the improving content of Wikipedia. I think that our own guideline should also be brought up to a higher standard as well. We have more good articles now then we did back then, and today's good articles are even "gooder" than yesterday's. Of course, given the confusion and disagreements here, bringing our guideline up to speed is likely still to be a long way off. But I think it should be a priority. Sławomir Biały (talk) 23:04, 22 January 2011 (UTC)

Some best practices

Here are some suggestions for the lead. I've itemized them for easier discussion.

  1. The lead should conform to WP:LEAD: The purpose of the lead is to define the topic and summarize the article with appropriate weight. (The proposed guideline of best practices is in addition to the requirements of WP:LEAD, which editors are encouraged to consult before continuing.)
  2. For a mathematics article, as a general rule, the lead should at a minimum include answers to the following questions: (1) What is it? (2) What is it useful for? (3) What field is it studied in?
  3. The lead should be as accessible as possible to those without a specific mathematical background. This may include providing a concise intuitive description of the subject, even if it isn't fully rigorous.
  4. Generally speaking, explaining things in words as opposed to mathematical symbols improves the accessibility. Likewise, if any specialized jargon appearing in the lead can be easily explained, it is a good idea to do so (even if in very informal terms).
  5. In spite of the goal of making the lead accessible, the lead should avoid teaching the subject. (WP:NOT#TEXTBOOK)
  6. Because of the constraints on the length of the lead, a separate "Introduction" or "Motivation" section may be warranted to allow a more complete intuitive description of the subject. However, like all content on Wikipedia, such a section is held to the same standards of sourcing (WP:V) and should be written in an encyclopedic and formal tone. These constraints may dictate the precise structure of such a section (it may take a historical perspective such as in Metric tensor, or the perspective of increasing generalization like Group (mathematics).)

--Sławomir Biały (talk) 23:40, 22 January 2011 (UTC)

Sounds good to me--Kmhkmh (talk) 15:49, 23 January 2011 (UTC)
There was an old change I was involved in that might be relevant. I set up a motivation and overview section in exponential function which was later changed to just "Overview". You might find the discussion at Talk:Exponential function#Slight muddle? and the next section. It seems there is a real desire in some editors to have article written in a purely logical fashion like some old textbooks where the final result only appears on the last page. I think there really is a need for explicit style guidelines in this area, though even here when I quoted the guidelines another editor responded very negatively to the ideas there. Dmcq (talk) 00:04, 23 January 2011 (UTC)
I agree with your thesis. I find that a good way to deal with people who say things like "I wipe my arse with the Mathematics manual of style!!" is to ignore them until they become interested in something else, and then to go ahead and whatever one was going to do anyway. This particular arse-wiping editor seems to have quit Wikipedia since the discussion you mentioned. —Mark Dominus (talk) 10:13, 23 January 2011 (UTC)

1) Should this discussion be moved to another location? Maybe the talk page of WP:MOSMATH, since I think it is a good idea to record the result of this discussion somewhere, for example as a section of WP:MOSMATH. 2) I generally agree with the points above. Something that could be add is that, if use of jargon is unavoidable, it is generally a good idea to avoid using more than one new piece jargon in a sentence. This way it is possible for readers with a vague acquaintance of the subject, but who are fuzzy on the jargon to get some idea of the meaning of the jargon from the context.TR 08:59, 31 January 2011 (UTC)

Perturbation problem beyond all orders

Perturbation problem beyond all orders could use some work. Michael Hardy (talk) 04:54, 30 January 2011 (UTC)

Accessibility of WP:Math (or "No, I don't have Dyscalculia but WP:Math is just facts and proofs.")

I know, I'm beating this horse over again going over the archives but there few issues and common themes that seem to repeat themselves. WP:NOTTEXTBOOK is often referenced (like in the FAQ above and essay reference) as the excuse for the difficulty of what it's hard to learn anything from WP:Math pages. I do not believe this fair that it's intended purpose. That was meant to leading questions followed by systematic problem solutions as examples. In that same section it states:

5. Scientific journals and research papers. A Wikipedia article should not be presented on the assumption that the reader is well versed in the topic's field. Introductory language in the lead and initial sections of the article should be written in plain terms and concepts that can be understood by any literate reader of Wikipedia without any knowledge in the given field before advancing to more detailed explanations of the topic. While wikilinks should be provided for advanced terms and concepts in that field, articles should be written on the assumption that the reader will not or cannot follow these links, instead attempting to infer their meaning from the text.

Also in right below that in that same section:

7. Academic language. Texts should be written for everyday readers, not for academics. Article titles should reflect common usage, not academic terminology, whenever possible.

This is the problem with the current state of WP:Math and it's infamous for this, both inside and out of the wikipedia community.

"Article titles should reflect common usage, not academic terminology, whenever possible." What is an example of an article title that follows "academic terminology" in preference to "common usage" that would say the same thing or something similarly adequate to the purpose? Michael Hardy (talk) 18:01, 30 January 2011 (UTC)
BTW, I agree with 5 and 7 above. And I've seen cases where they're violated, and tried to fix them. But far more often they are followed. Michael Hardy (talk) 18:06, 30 January 2011 (UTC)

I've done my part in the past few years to link jargon to appropriate pages, fix circular definitions across pages by providing an entrance for someone trying to find an in, and created a few images (all of which to been replaced by better ones it seems). I totally get that it's one it's one of the best resources for the intelligentsia and I don't want to diminish that but that isn't the goal of an encyclopedia. I recently was shocked when I popped in an old copy Encarta and compared the text of our math articles. The articles are brief but you can actual pick up the topic if you not an expert. I feel a little overwhelmed though and hope someone hears and understands the community's pain. --ZacBowling (user|talk) 11:05, 30 January 2011 (UTC)

Sigh. Sigh. Sigh. Yes, you're beating the same horse again. There are a few misconceptions on your side. First, if you think that every topic could be made accessible to laymen then why not start with the hardest topic of all ("rocket science" so to say) and after reading the article you'll be an expert. Is that what you have in mind? Second, we have just been discussing right on this very page the issue of accessibility (scroll up). If you have constructive suggestions on how to improve exterior algebra, which have been praised for the recent improvements, you are welcome. Third, pillar one states that "[Wikipedia] incorporates elements of general and specialized encyclopedias, almanacs, and gazetteers.", emphasis on "and specialized". Last but not least, the last two words of point 7 read "whenever possible". Nageh (talk) 11:17, 30 January 2011 (UTC)
Ad "WP:Math is just facts and proofs": Facts and proofs are inherent to abstract and formal sciences. As long as it's not Euclidean geometry it's hard to draw pretty pictures to visually demonstrate the problem. Nageh (talk) 11:20, 30 January 2011 (UTC)
"Texts should be written for everyday readers, not for academics. Article titles should reflect common usage, not academic terminology, whenever possible" - this is impossible. Math is about rigor, you cannot replace strictly defined terms with colorful metaphors - except for the lede, 'Introduction' and 'Motivation' sections, where it is permissible to some degree. If you think math can be done the way liberal arts are, you are sadly mistaken — Kallikanzaridtalk 11:41, 30 January 2011 (UTC)
I sympathize with user ZacBowling. The kind of Bourbakist rhetoric people get for voicing frustration over inaccessibility is discouraging. Tkuvho (talk) 11:45, 30 January 2011 (UTC)
The point where many mathematical articles (admittedly) can be improved are the lead and introductory sections, as Kallikanzarid has pointed out. However, it is impossible to dumb down the core of most articles without getting rid of advanced topics all together. Otherwise, as I suggested, why not skip all the basics, all the elementary and high school stuff and start right with the most advanced topics assuming it is all a matter of presentation? Nageh (talk) 11:51, 30 January 2011 (UTC)
You again? :D You're funny and all, but one more time and I'm reporting you for being a troll — Kallikanzaridtalk 12:04, 30 January 2011 (UTC)
Certainly more can and should be done to increase accessibility; but this has to be within a framework of reasonable expectations. It is somewhat misleading, for example, to make comparison with cutting-edge physics, where a one-hour documentary can make you feel that you have clue about the Higgs boson or strings; when in fact the content doesn't give you access to the simplest computations or basic intuitions in quantum theory at all. Reasonable here means that topics up to about first year graduate study, for which there are adequate and fairly stable textbook treatments, should be presented with some of the heuristic remarks that might well accompany lectures. Saying that Galois discovered that polynomials exhibit hidden symmetries is probably OK; that group theory and field theory help to express the idea conveniently is OK too. I have seen too many such "loose" remarks cut out of lead sections over the years. Have a look at back versions of spectral sequence to see what I mean: the current version really assumes you first know what an abelian category is, which would have been news to the users of spectral sequences in their great period 1945-1960. So some pushback is necessary. But on the other hand the trouble you can get in is illustrated by this, which I happened upon this morning. Trying to be overly heuristic about the Riemann Hypothesis tangles you up with describing the state of research on the primes, which is trouble we don't need in basic exposition (it is very much "facts and proofs" to describe the state-of-the-art in serious topics).
Therefore a "reasonable" way forward would seem to me to be to delineate "core" topics of advanced mathematics and to try to bring their exposition up to scratch, at least where all heuristics are probably out there in the literature and just need to be referenced. Vague remarks that contain elements of OR are also against key policies. Charles Matthews (talk) 12:05, 30 January 2011 (UTC)
One of the main problems is that individuals like Kallikanzarid who have shown their lack of understanding of some of the more advanced issues, continue to edit pages as well as expressing themselves in a virulent fashion throughout wiki. The problem with accessibility at exterior algebra has not yet been resolved, partly due to the lack of understanding of some of the participants. Tkuvho (talk) 12:11, 30 January 2011 (UTC)
I might say the same thing, although with a slightly different emphasis... Sławomir Biały (talk) 13:46, 30 January 2011 (UTC)

FWIW, I have always in interpreted the "academic language" section to be referring to articles like apple that are commonly discussed in non-academic settings. It would be possible to fancy up that article with a lot of terms from biology, for example by saying "endocarp" instead of "core". But the common term for the core of an apple is "core".

The intended audience for apple is much broader than the intended audience for Galois cohomology, and it would be silly to expect the latter to be accessible in the same way that the former should be. The common, everyday word for "homological algebra" is "homological algebra"; there is no other, more common, term to use.

The "research papers" section, which claims that readers should not need to follow wikilinks, has been at odds with actual practice for years, and should generally just be ignored. This is not just in math; see B flat major for another article that you couldn't read unless you knew many terms. The lede of that article is also full of specialized terminology, and is also perfectly appropriate. — Carl (CBM · talk) 12:27, 30 January 2011 (UTC)

I'm not sure what the end result of all this discussion is going to be. I like User:Sławomir Biały's best practices listed above and perhaps they should be added to MOSMATH before they disappear into the archives forever. Some, perhaps most math article could be improved in terms of accessibility, and there are several reasons that some articles have to be less accessible than others. But I don't see any specific changes to MOSMATH or anything else concrete that can be decided here being suggested. I'd like to add that, while WPMATH has a large number of articles, it has a relatively small number of editors working on them. So I think some recognition is due to this project for getting math articles into the shape they're in now, even if it's still a work in progress.--RDBury (talk) 14:20, 30 January 2011 (UTC)

This section's heading looks like someone didn't pay much attention before posting. "Just facts and proofs"? There aren't very many proofs in Wikipedia math articles. Proofs are something we have very little of here. Michael Hardy (talk) 17:57, 30 January 2011 (UTC)

I was quoting a CS professor I know from Berkeley. We had a long conversation about it since I'm fairly active in the community here. --ZacBowling (user|talk) 00:56, 31 January 2011 (UTC)

I'm a software engineer myself with a focus on user experience so that is where my brain goes. (coincidentally I used to work a TI developing the software for graphing calculators). Here are a couple of ideas:

  • The <math></math> tags should be a little more accessible when used. It's more a technical challenge (my kind of thing), but I would be nice if math symbols could optionally link to topic articles in the syntax.
  • A common info box that links to the areas of math the page is directly related too (set theory, elementary algebra, etc), sub categories with pages (eg: matrix calculus), and a field for an optional list of areas of math, physics, and other sciences that the topic can be applied too.
  • If someone has stumbled into a page that requires knowledge of a general topic to even understand the current page, the page should within the first few sentences state that and give a link back to a topic. A bunch of pages simply say "In mathematics," and then a list of topic specific jargon. If you are lucky, you find a category tag or hit the talk page and see area of math the topic is trying to cover (like Schubert variety and Bender–Knuth involution)

It's sad that WP:Math is the only Wikipedia area that makes me feel like I should be using Simple English Wikipedia. --ZacBowling (user|talk) 01:56, 31 January 2011 (UTC)

Re "It's sad that WP:Math is the only Wikipedia area that makes me feel like I should be using Simple English Wikipedia." This is more a function of mathematics than Wikipedia's treatment of mathematics. Paul August 02:01, 31 January 2011 (UTC)
Hmm. I think it would be nice if our articles had more navboxes. For instance, take my own dear field of algebraic geometry. It has the generic "areas of mathematics" navbox at the bottom. Now, someone interested in browsing algebraic geometry articles could go to Category:Algebraic geometry, but that category has hundreds of entries plus subcategories. The algebraic geometry article spends most of its time on foundational issues like what varieties and schemes are, and nowhere does it give the reader a map of the subject. A much cleaner solution would be to have a navbox. I think that wider use of navboxes would to some extent address the second and third bullet points above. (I don't know what to do about the first, though.) Ozob (talk) 02:44, 31 January 2011 (UTC)
Since algebraic geometry makes no attempt to use summary style (WP:SUMMARY), something could certainly be done there by quite conventional means. The imposition of a section on "derived algebraic geometry" (no refs) makes it look pretty haphazard. Charles Matthews (talk) 08:20, 31 January 2011 (UTC)
Yes, I think the article is in sad shape. But writing a good survey article for an entire field of mathematics is very, very hard. As an entirely inadequate band-aid, I have created Template:Algebraic curves navbox. It is large and unwieldy, but I think it is a pretty accurate survey of the important topics in the theory of algebraic curves. At least, of those we have articles on. (E.g., I didn't find an article on Mori's bend and break or on rational connectedness, both of which I think would be nice additions. And I couldn't find a really appropriate article on the Riemann–Hilbert correspondence for curves and all of the wonderful stuff related to it (representations of fundamental groups, etc.).)
I am not too attached to the organization that I chose. Classifying everything in some way, let alone a good way, was plenty hard. It may be better to break this into several navboxes, but I'm not sure what would be better. Also I am sure I've made mistakes and left out important things. For the moment I've added the navbox to algebraic curve, elliptic curve, plane curve, and Riemann surface, but of course anyone should feel free to add it to appropriate articles. Ozob (talk) 04:10, 1 February 2011 (UTC)
I have to say that a navbox link is a poor substitute for a {{details}} link, when it comes to exposition and structure. Charles Matthews (talk) 08:03, 1 February 2011 (UTC)
Ozob's navibox is very helpful and well-designed. May there be more like it. Tkuvho (talk) 09:16, 1 February 2011 (UTC)
Well, I've thought about rewriting the algebraic geometry article into a good survey article, but I'm too intimidated by the scope to actually try. Even the algebraic curves navbox is much less than I had initially set out to do. I started out trying to do an algebraic geometry navbox, and I was entirely overwhelmed: Either it was going to be too huge for me to make or it was going to be too selective to do its job. Curves are a specific enough subject that making a navbox like this was actually feasible. And while I agree that navboxes may not be as useful as a survey article, they are a lot easier to do. Ozob (talk) 11:40, 1 February 2011 (UTC)

Some candid observations

I have some relevant thoughts on the original post of this thread. The fact is that there are a great many mathematics articles that are inaccessible, and I don't think anyone can credibly deny this. There are plenty of terrible mathematics articles, some of which no doubt I myself have inflicted on the world. I do think that improving the accessibility of mathematics articles is an important and worthy goal, and I think the best we can hope for in general discussions here is a systematic solution, such as bringing the MOSMATH in line with our current best practices. But project members often display a lack of concern for these issues, or at least a lack of sensitivity to them, and various often sinister reasons have been ascribed for this. But I would like to make some candid observations that I think help explain why things are this way.

Wikipedia's mathematics editors seem to be mostly academics of one stripe or another, and this also seems to be less true of other content areas. To some extent, this dictates how our coverage of mathematics topics develops. I have written articles for the following reasons, and I think that so have many other mathematics editors if I had to guess at their motives based on their behavior: (1) to understand the topic of a seminar I am involved with, (2) as a convenient reference for myself (and other researchers), (3) as a resource for my students (who may be undergraduate or graduate students), (4) to help learn a subject myself or out of sheer curiosity of a subject that I know little about. While I'm sure that the whole altruistic "free encyclopedia" thing may make us feel good about our contributions, it's much too rarefied to elicit any real work on the encyclopedia (for me, at any rate). Out of my own motivations (and I presume those of others), very little has to do with making the encyclopedia accessible to Joe on the street. The only time accessibility is a big personal concern is when I am writing for students, but in their case I assume a fairly specific background (especially when they are graduate students) that the wider population isn't likely to have.

Wikipedia's mathematics editors themselves are also products of the wider world of mathematics, which seems to lack expository source material aimed at Joe on the street. For us, articles published in the Notices of the American Mathematical Society are expository, although most of these articles are almost certainly not understandable to Joe. The rest of the sciences have serious expository outlets like Scientific American, the American Scientist, Nature, and Science, that attempt to explain cutting-edge developments in the sciences to laypeople. But mathematics has no such outlet: Journals in mathematics that specialize in exposition do not emphasize mathematics that is of substantial contemporary interest. One can attempt to rationalize this by saying that "It's the nature of the subject" and "It's much more difficult to make mathematics accessible than other content areas". Critics here dismiss these rationalizations as mere excuses, but I think it is significant that there are so few expository sources for most of mathematics. Sławomir Biały (talk) 13:06, 31 January 2011 (UTC)

It is quite true that mathematics generally is short of survey articles. Let's assume that this WikiProject really could solve three problems:
  1. Writing surveys that would help mathematicians get into topics not in their specialist area;
  2. Writing surveys that would help non-mathematicians get into topics; and
  3. Writing material that would help anyone read the contemporary literature on the Web (and elsewhere).
Then the summary of a great deal of debate comes out that #1 and #3 are handled better than #2. Complaints that aim at #3 (NB what recent papers typically lack is definitions and basic facts), as a way of sorting out #2, are misguided. I think we saw this during a flurry of interest in E8 in the media not so long ago: the media reports were essentially without content, while we added some material on Kazhdan-Lusztig polynomials that meant the actual result could be stated clearly. What #2 would require in that context is exposition of exceptional Lie groups (for example for a chemist), not an attempt to say what the research had been. Charles Matthews (talk) 13:51, 31 January 2011 (UTC)
"there are so few expository sources for most of mathematics" - what about The Princeton Companion to Mathematics? --Boris Tsirelson (talk) 07:00, 1 February 2011 (UTC)
I concur with Boris. There are plenty of expository sources. The japanese encyclopedia is an excellent source. Most of their articles start with the simplest nontrivial example of a theory about to be developed, and works out the example before proceeding to generalisations. The idea that mathematics is somehow different from other scientific fields (and hence hard to explain) is a lame excuse for indulging in Bourbakism. Tkuvho (talk) 11:12, 1 February 2011 (UTC)

I clearly said that advanced mathematics generally lacks expository sources aimed at Joe on the street: that is, aimed at a completely non-mathematical audience. I wouldn't argue that there are expository sources aimed at mathematical audiences. The Princeton Mathematical Companion is pitched at about the same level as many of the "Notices" articles, and most of it is not accessible to Joe on the street. But I think this is a good example because it illustrates about the right level of expository style for several distinct groups of people in this discussion: those who wish to improve the accessibility of portions of our encyclopedia, those who feel that the compendious style of many of our articles is ok, and those that post here to complain that mathematics articles are inaccessible. There is obviously tension between these three groups, and getting them to agree on an acceptable style might be one way forward. Sławomir Biały (talk) 12:42, 1 February 2011 (UTC)

Also, what is the Japanese Encyclopedia? I'm familiar with Ito's Encyclopedic dictionary of mathematics, though I would emphatically disagree that the exposition in that text would be comfortable to non-mathematicians. Sławomir Biały (talk) 12:45, 1 February 2011 (UTC)

That's the one I had in mind. I see that you emphatically disagree about non-mathematicians. Let's leave them aside for a moment. The expository style of Ito's series is attractive because it is geared to explaining basic things rather than trying to cover as much ground as possible. That's a guideline that we should adopt as well. But first we need to get away from the idea that this is somehow "impossible" due to the inscrutable nature of mathematics. Only Bourbaki is inscrutable. I am a great fan of category theory, by the way, and its spectacular applications such such as synthetic differential geometry. But every thing has its place. Tkuvho (talk) 13:47, 1 February 2011 (UTC)
I agree that we should strive not to be Bourbakist. The expository style of either Ito or the Companion is definitely appropriate for a mathematically mature audience. However, I'd like you to please read again what I originally wrote, you will see that I am here talking exclusively about the problem of making things accessible to a non-mathematical audience. Sławomir Biały (talk) 13:53, 1 February 2011 (UTC)
We will never be able to make this accessible to Joe in the street. Your thread is a sub-thread of an earlier thread where useful ideas such as introductions and navboxes were discussed (and some created since). I think we should orient ourselves on people like the originator of the larger thread, who obviously have technical training in college mathematics. Generic discussions of whether "dumbing things down" for a scientific audience is possible or not possible are not going to get us anywhere. You can participate in the current improvement of the algebraic curve group of pages if you believe such improvement is possible. Tkuvho (talk) 14:11, 1 February 2011 (UTC)
But it does seem relevant in relation to the highlighted points from WP:NOTTEXTBOOK in the previous section, which refer to "any literate reader". If we can at least agree on an appropriate way to cover advanced mathematics, then this would indeed be progress. It would help if this were enshrined in some guideline, since the letter of WP:NOTTEXTBOOK would seem to (wrongfully) exclude most of our mathematical content. Sławomir Biały (talk) 14:22, 1 February 2011 (UTC)
Glad you are back. This is an important issue. Perhaps "literate" should be made more specific with reference to mathematics to mean "scientifically literate". This should be discussed in a separate thread. Tkuvho (talk) 14:29, 1 February 2011 (UTC)

List of mathematics journals

I have been working recently on List of mathematics journals. The list was pretty much unattended for a while, and recently some editors from the Academic Journals wikiproject asked us to clean it up. Journals aren't our core focus, but this list is certainly in the broad scope of the math project, as well as the scope of the journals project.

There is a notability "essay" WP:NJournals, which apparently has some weight at AFD discussions, which says that (as one possible criterion) if a journal has an impact factor and is indexed in Math Reviews and Zentralblatt MATH, then we can create an article on it. So I have pruned the redlinks on the list to journals that meet those criteria, and I am working on creating the articles. I made a journal article helper program that can help format the information about a journal into a reasonable stub. If you're interested, you can look up information on your favorite redlinked journal and make a stub article about it (this is easiest if you are at a computer with access to MathSciNet and Journal Citation Reports). — Carl (CBM · talk) 15:17, 1 February 2011 (UTC)

Math related FP nomination

Another pair of cellular automata animations have been nominated, see WP:Featured picture candidates/Non-intermediate phases of BML Traffic Model. See are related to the CA animations that were promoted to FP a week or so ago.--RDBury (talk) 16:01, 1 February 2011 (UTC)

Flat function

The article titled Flat function is somewhat orphaned, i.e. very few other articles link to it. This sort of function plays an important role in the theory of test functions, used in developing generalized functions. It also is used to show why complex differentiability is so much stronger than real differentiability. There must be other things that ought to link to it. Michael Hardy (talk) 20:06, 1 February 2011 (UTC)

I just added a link from the "See also" section of power series. Michael Hardy (talk) 20:08, 1 February 2011 (UTC)

Accelerated PSO

I declined a WP:PROD on this article but am sending it to AFD on request from the original PRODer. Some input from those familiar with computer science and mathmatics would be helpful. The discussion can be viewed here. --Ron Ritzman (talk) 01:40, 3 February 2011 (UTC)

Dehn plane

The Dehn plane article is up for deletion. While plausible searching the usual suspects Planet Math, Encyclopaedia of Mathematics don't yield and references.--Salix (talk): 05:28, 3 February 2011 (UTC)

Bourbakism or provocation?

User:Tkuvho continues to accuse me of Bourbakism. He feels that the lead of Exterior algebra, because it mentions the universal construction, is "engaging in Bourbakism" (whatever that means). Could someone else please comment on what he means? Is he right and I just don't see it? Or is he just trying to provoke me? If so, it's working and it needs to stop. Sławomir Biały (talk) 12:33, 1 February 2011 (UTC)

I agree that there is nothing Bourbaki-esque about that lede. The Bourbaki treatment can be seen on Google books, on p. 507 of Algebra [25]. In stereotypical Bourbaki style that section starts with a formal definition. It's about the opposite of our article. — Carl (CBM · talk) 12:46, 1 February 2011 (UTC)
The specific case of exterior algebra needs to be discussed separately. As far as Bourbakism is concerned, this type of formalism is a common problem that a number of outside scientists frequently complain about, it is about time to give it a name and see what we can do about it. Now returning to exterior algebra, the shape of the lede as you currently see it is the result of a tooth-and-nail fight of which you may not have followed all the intermediate stages. It took a massive effort just to have a reference to cross product restored. Some additional elementary topics are yet to be restored. Note that it was originally deleted on the grounds that "it is already covered under determinants", which is a typical bourbakist way of looking at things. Similarly, I had to fight to have some of the superfluous category theoretic language deleted, such as the following passage: "In terms of category theory, the exterior algebra is a type of functor on vector spaces, given by a universal construction. The universal construction allows the exterior algebra to be defined, not just for vector spaces over a field, but also for modules over a commutative ring, and for other structures of interest." As a result of my criticism, this has been replaced in the current version by "The association of the exterior algebra to a vector space is a type of functor on vector spaces, which means that it is compatible in a certain way with linear transformations of vector spaces". Note that references to "category theory", "universal constructions", and such have been severely curtailed as a result of my criticism. I am not sure why I am accused of criticizing shortcomings that are not there. Once they were removed following my criticism, they are certainly not there anymore. As far as applying the said "universal construction" to the space of sections, this is a rather advanced topic that requires no fewer than 5 stages to develop: (1) linear algebra, (2) topological stage to define the vector bundle, (3) analytical stage: sections of said bundles to prepare for applying the exterior derivative, (4) forming the infinite-dimensional space of said sections, and finally (5) noticing that the formal algebraic construction applies at the level of the said infinite-dimensional space of sections. Presenting stage (5) as if it were identical with stage (1) is simply mind-boggling and can only be attributed to a Bourbakist mindframe. Notice that I was the first one to state, on this page, that exterior algebra is a great page. It became even better as a result of my criticisms. There is still some residual "functor" jargon to be eliminated. Tkuvho (talk) 13:16, 1 February 2011 (UTC)
Wow. You have really invented a whole slew of facts to support your personal campaign against me. Firstly, the original removal of the cross product from the first paragraph, over my own better judgment, was the result of discussion with Jakob, who felt that it obscured rather than elucidated the meaning of the exterior product. The discussion of the cross product was then re-introduced without any fanfare at all by User:Nageh, and I think in a better way. (Hardly the tooth and nail fight that you make it out to be.) The material on minors was not removed because "it is already covered under determinants", it was removed because it was not covered in the rest of the article proportionally to its coverage in the lead that most participants in the discussion felt that was too long. The wording in the third paragraph was changed days before you made any input at all on the matter (thus it hardly "As a result of [your] criticism..."). Finally, your last comment is wrong on at least two points: (1) that the universal construction is anywhere being mentioned in the article in connection to differential forms (one can use the universal construction, tensor products of modules, tensor products of bundles, or whatever approach one likes to the subject—the only thing the article says is that it is "one of these more general constructions"), (2) that because it is complicated, the lead should not mention it (the language used in the lead doesn't in any way suggest that the generalization is trivial, although perhaps the body of the article could say more about the details). Sławomir Biały (talk) 13:45, 1 February 2011 (UTC)
Bialy, let's leave aside what you call the "campaign" and concentrate on the issues. This is getting tiresome. I was not the one to bring up exterior algebra a few minutes ago. Please consult the end of the previous thread. Tkuvho (talk) 13:48, 1 February 2011 (UTC)
Yes, it is getting tiresome. I do not appreciate the accusations of "Bourbakism". It's really quite irritating (not to mention unfounded in the example that we know you have in mind). Please stop. Sławomir Biały (talk) 13:55, 1 February 2011 (UTC)
Incidentally, if you want to apply the construction to vector bundles or tensor products of bundles, then you are not applying the exterior algebra construction to a vector space (as in the case of the space of sections), but rather applying it pointwise to every fiber. This is exactly the ambiguity that I pointed out repeatedly on the talk page, and it is still there in the lede and can lead the reader to errors. I never called you a Bourbakist. I am criticizing a certain style of writing in mathematics. This is a very common term in the "community". It no longer has that much to do with Bourbaki themselves (which started out before category theory). It was not meant as a personal attack. If it is any help, I apologize for giving you such an impression. Tkuvho (talk) 14:00, 1 February 2011 (UTC)
I think that any interpersonal aspects of this should be moved to user talk pages.
I don't like the idea of using the word "Bourbaki-ism" to refer to "not clear enough". Bourbaki is a particular group of people, and the name Bourbaki has the connotation of the actual writing done by those people, which many mathematicians have had exposure to. The problems people sometimes perceive in Bourbaki's writing are broader in some ways and narrower in others than the perceived problem on Wikipedia articles. Because our problems are not the same as Bourbaki's, we don't want to label our problems with that name. — Carl (CBM · talk) 13:58, 1 February 2011 (UTC)
You are not relating to the way the term is used in the "community". It does not just refer to "not clear", and it does not refer specifically to Bourbaki writing. For instance, Bourbaki did not develop category theory, but everyone knows what I mean when I say that emphasizing category theory in a lede of exterior algebra is Bourbakist. Luckily, the emphasis has been significantly curtailed by now. Tkuvho (talk) 14:02, 1 February 2011 (UTC)
Bourbaki did not emphasize category theory very much, and worked with set-theoretic foundations instead. Indeed, the lack of category theory is a criticism often made about Bourbaki. This is the type of thing that I mean when I say that the criticisms of Wikipedia articles are not the same as the criticisms of Bourbaki. The word "Bourbaki-esque" has to be used to refer to Bourbaki's writing, because that writing is such a well known aspect of 20th century mathematics that it is difficult to separate the name from the work.
On the other hand, topics such as Exterior algebra should mention category theory, because that is the standard language of modern algebra. If a construction is functorial, our article should say so; that's exactly the type of information that our articles are meant to contain. — Carl (CBM · talk) 14:16, 1 February 2011 (UTC)
Carl, you have not been reading the discussion very carefully. Of course it should be mentioned at exterior algebra! What I was arguing is that the lead is not the place for it. At any rate, the current categorical content of the lede is quite minimal, and I see the controversy is taking a toll on some of the participants. If it is deemed uncontroversial perhaps some of the deleted references to elementary concepts such as rank and minor can be restored. This is a minor issue in an otherwise excellent page. As far as Bourakism is concerned, you may not like it but it is routinely used in the sense I used it. I am not sure it is our role to fight custom in this case. Tkuvho (talk) 14:26, 1 February 2011 (UTC)
Please see WP:LEAD. The lead is supposed to summarize the article, much of which is devoted to functorial properties and the universal construction. Sławomir Biały (talk) 14:29, 1 February 2011 (UTC)
OK, well, hope you like my latest change to the lede. Glad you are back. Tkuvho (talk) 14:31, 1 February 2011 (UTC)
Re Tkuvho. Personally, when I hear mathematicians criticize Bourbaki, it is for an overlapping but non-identical set of reasons compared to the reasons people criticize Wikipedia articles. Moreover, in practice, our articles do not resemble Bourbaki's writing very much. So criticisms that our articles are "Bourbaki-esqe" always strike me as somewhere between polemical and naive; either way, it makes me take their argument less seriously. If that's the goal, then by all means keep using the word. I think you be able to convince more people if you phrase your criticisms in other terms. — Carl (CBM · talk) 14:36, 1 February 2011 (UTC)

Bourbakism or excessive formalism?

What term would you suggest then? Excessive formalism? Jargon-filled brow-beating? Somehow they are not as effective. Tkuvho (talk) 14:41, 1 February 2011 (UTC)
Or you might just try to be a little less polemic. You might find that this makes others more amenable to constructive discussion.TR 15:09, 1 February 2011 (UTC)

Let's ask that everybody avoid personal attacks. It may be wise for some participants to take a few days off, for their own good and the project's. The participants have been very valuable members of WP and this project.  Kiefer.Wolfowitz  (talk) 15:20, 1 February 2011 (UTC)

Two quick examples of what might be considered excessive formalism: at natural number, for years the article opened with a definition that spoke of the set (mathematics) of natural numbers. I took the "sets" out of the lede. This was my successful anti-Bourbakist operation. Second example: at first-order logic, I tried to include a sentence in the lead to the effect that "first-order" means quantification over individuals, whereas higher-order involves quantification over sets. Now this is technically not quite correct. Still, a lot of people think this remark clarifies the nature of the term "first-order". But because it was not 100% technically correct, my change was mostly reverted. That's my example of a not completely successful anti-Bourbakist operation. Tkuvho (talk) 17:37, 1 February 2011 (UTC)

I think I'd reserve the term "Bourbakism" for articles that start immediately with the most general possible approach to a topic that doesn't warrant it. On several occasions Bourbaki use monoids where most people would be happy with groups, or when they first develop integration they do it for arbitrary locally compact spaces (which I'm quite happy with, but would be the wrong place to start on wikipedia). I completely disagree with saying that mentioning category theory or functor in the lead of an article is "Bourbakist" and more importantly I disagree that it is wrong. Exterior algebra isn't the article "Prime number", it's an article about a formal algebraic tool. A tool which is commonly used in a functorial way. Almost nobody actually takes the exterior algebra of a vector space (at the very least, people use it for a module over a ring, or a representation of a group). If there is an article whose problem is unnecessary use of jargon, then it's problem is "unnecessary use of jargon", not "Bourbakism". For example, using "set" in the first sentence of the article "natural number" is an unnecessary use of jargon. An infringement that would more merit the term "Bourbakism" would be some sort of high-brow axiomatic description such as "In mathematics, the natural numbers are the standard model of Peano arithmetic." RobHar (talk) 17:48, 1 February 2011 (UTC)

The natural numbers are the free monoid generated by a one-element set: that would be excessive formalism. — Carl (CBM · talk) 20:10, 1 February 2011 (UTC)
Bourbakism is good. --Matt Westwood 19:01, 1 February 2011 (UTC)

Actually the knack is to take out excess "mathematics made difficult" formalism, while not being "anti-Hilbert" (retaining the idea that mathematical concepts are axiomatic and "sharp-edged", not vague). And being entirely accurate in what is said, unless flagged up with language such as "roughly speaking". Charles Matthews (talk) 20:34, 1 February 2011 (UTC)

That's a pretty good summary of the challenge. I think we are in agreement that there is room for improvement in a number of cases. The important thing is not the label, but the recognition that there is a challenge. Keeping an eye on reducing "mathematics made difficult" formalism, combined with some work on introductions and navboxes, would probably go a long way toward making our colleagues in the sciences less frustrated with our pages. Tkuvho (talk) 21:19, 1 February 2011 (UTC)
Just a quick additional comment about Hilbert's axiomatics: we all agree about its fundamental importance. At the same time, it was not necessarily meant to be a pedagogical tool. Peano tried to apply the purely axiomatic approach in his own teaching, with disastrous consequences documented at our page for him. I would ahistorically call that Bourbakism, because that's the way the term is used in the "community". People have pointed out above that this is may not be related to Bourbaki proper, which is also a good point. Tkuvho (talk) 09:25, 3 February 2011 (UTC)
Wikipedia, also, is "not necessarily meant to be a pedagogical tool". It's a reference site, primarily.
The issue of long chains of logical dependencies is an expository one, inherent in axiomatic subjects, and it is natural for us to try to solve it by means of wikilinks. We should continue to do that (no choice in fact); it has been noted that in the medical area we tend to assume people will follow the links if they need definitions, while professionally-written material uses a great deal more paraphrase into layman's language. I think we could make some progress here by working towards a "style guide" paragraph or two on how to use paraphrase in mathematics articles. There is an obvious issue of finding an appropriate register of language, and mathematicians have much less practice than physicians in that matter. Charles Matthews (talk) 10:49, 3 February 2011 (UTC)
In my view, this issue of "long chains of logical dependencies" that Charles mentions above is a key one here. These long (and exacting) chains in mathematics can be extremely tedious and time consuming to follow (as every mathematicians becomes painfully aware when they try to read any mathematics outside their specialty). The length of such chains in mathematics is significantly (rough guess, at least an order of magnitude?) longer than in other fields, and that non-mathematicians greatly underestimate this difference, leading to considerable frustration. It would be interesting if there were some objective measure of the average length of such chains in various fields. Paul August 14:31, 3 February 2011 (UTC)

Dependency bot

The above discussion gave me an idea — let us have a new bot which looks at the lead of an article and assigns it a number which is the smallest natural number greater than the numbers assigned to the articles to which it is linked. If it is not possible to calculate such a number due to a closed loop in the links, then it would report that fact and give a list of the links in the loop. This tool could be used to try to break circular definitions and reduce the depth of searching which readers have to do to understand the lead. JRSpriggs (talk) 13:24, 3 February 2011 (UTC)

That would not be too difficult, technically speaking. It could be done by starting at a given article and chasing links until there are no more. Unfortunately, my time at the moment is committed, but I'd be very interested in seeing the results.
One concern I have is with loops (even in the lede) of a "see also" kind. For example,
  • Recursion theory is a branch of mathematical logic.
  • Mathematical logic is often divided into the fields of set theory, model theory, recursion theory, and proof theory.
However, without actually generating some numbers, it's impossible to say how common that issue would be. — Carl (CBM · talk) 13:35, 3 February 2011 (UTC)
My suspicion is that such loops occur in almost all cases. From an accessibility point of view this is not really a problem since such links typically inform the reader of parallel articles on closely related subjects, one of which may in fact be more appropriate for the specific info that the user was looking for. (Knowing "what to search for" already requires quite some familiarity with a subject.)
Moreover, such links are useful since people come from different backgrounds, some readers will be familiar with A but not B will others will be familiar with B but not A. If A and B are similar in some sense, then both these groups will be well served by the leads of A and B pointing out the similarity and linking to the other article.TR 14:09, 3 February 2011 (UTC)
This particular issue is resolved to a certain extent by navboxes. While it is obviously not a solution to all ills, a hierarchical structure of a navbox can help the reader break out of a logical loop. Thus, we could create a navbox for linear algebra with three levels, beginner, intermediate, and advanced; here rank, minor, determinant, cross product would go at beginner level; exterior algebra and other college-level topics would go in intermediate level; advanced topics could connect to differential graded algebra, etc. This way a reader who is having difficulty with "exterior algebra", instead of getting frustrated with links that lead to other intermediate or advanced topics, could go where he should go first, namely the elementary topics which are prerequisites for exterior algebra. Two people involved in this discussion have already created navboxes. Give it a try! Tkuvho (talk) 14:28, 3 February 2011 (UTC)
I don't see exterior algebra as a college-level topic except possibly for a few exceptional students are a few very strong universities. Maybe this is a matter of different universities doing things differently, but I think of the algebra content of a "typical" undergraduate mathematics degree as including just the basic group, ring, and field theory, some basic linear algebra (maybe through Jordan canonical form), and probably a little basic Galois theory. I wonder if there is any information on what topics really are common at the undergraduate level. — Carl (CBM · talk) 14:47, 3 February 2011 (UTC)
I agree that it would be the rare college level student that would be taught this. In fact the same might be true for the average topology graduate student. I don't recall seeing this, nor does a quick glance in my three graduate algebra books (from the late sixties, early seventies) find any mention. Paul August 15:16, 3 February 2011 (UTC)
I agree, it is not really an undergraduate topic. Obviously whether or not it is taught depends strongly in the interests on the faculty. My argument in favor of navboxes is independent of the issue whether exterior algebra is an undergraduate topic (replace "intermediate" level in the navbox by "advanced", and "advanced" by "research" :) ). Tkuvho (talk) 15:18, 3 February 2011 (UTC)

Affine Grassmannian

The article on affine Grassmanians AGr(n;k), i.e. the k-dimensional affine linear subspaces of an n-dimensional vector space need some additions. For example, it says that as a homogeneous space it can be realised as

At first it didn't even say what O(nk) was, never mind link to the article. (It's the orthogonal group and E is the Euclidean group.) I think this expression needs explaining. I'm half way to understanding it, but not completely. You start with a k-dimensional subspace passing through the origin, say S0. You can move that onto any other k-dimensional affine subspace, say A0, by a Euclidean transformation; so we start with E(n). But different Euclidean transformations take S0 to A0; look at the image of the origin when you take S0 to A0. That's why we quotient out E(k); we get a map A0A0 given by different Euclidean transformations taking S0 to A0. This is where I start to get stuck. I can see that the O(nk) term comes from the different choices of original subspace instead of S0. But that's just the ordinary Grassmannian Gr(n;k) and not O(nk). Could some one possibly explain to me where O(nk) and then add the explanation to the article itself? Fly by Night (talk) 16:27, 4 February 2011 (UTC)

Take a set of all lines in R3, for example. E(3) acts transitively on them, so you have to find what transformations leave a fixed line in place. There are naturally two kinds of them: euclidean transformations of the line itself and (improper) rotations of the space around that line as an axis. Thus the isotropy group is E(1) × O(2)Kallikanzaridtalk 18:51, 4 February 2011 (UTC)
I see, but how would you phrase that in terms of my S0 and A0? In terms your more general approach, what is the general theorem at work? If you have a Lie group G acting transitively on manifold X by α : G × M → M, then M is isomprphic to to the quotient G / Gx, where xX and GxG is the isotropy subgroup of x? This reminds me of the first isomorphism theorem which says that if φ : G → H is a homomorphism then φ(G) ≅ G / Ker(φ). Is that where the proof comes from? If not, could you leave me a link or a reference? I need to understand this for some work I'm doing; but I'm more of a geometer than a group theorist. Thanks. Fly by Night (talk) 21:03, 4 February 2011 (UTC)
"If you have a Lie group G acting transitively on manifold X by α : G × M → M, then M is isomprphic to to the quotient G / Gx, where xX and GxG is the isotropy subgroup of x?" Yes, but please note that it is a quotient of manifolds, isotropy group is not required to be normal. It makes sense if you think about it :) I am not very familiar with the subject myself, for a rigorous explanation refer to homogeneous space; the second volume of Kobayashi–Nomizu has a chapter about homogeneous spaces, but I haven't read it myself yet. — Kallikanzaridtalk 22:04, 4 February 2011 (UTC)
Great, thanks. When one of us has read that chapter we ought to improve the article I mentioned at the top too. I didn't mention normal subgroups. As far as I recall GxG means that Gx is a subgroup of G. While means that Gx is a normal subgroup of G. Thanks again. Fly by Night (talk) 01:37, 5 February 2011 (UTC)

Plücker coordinates

There seems to be a big flaw in this article. The space of lines in P3 is a projective concept. Yet Plücker coordinates are defined in terms of a Euclidean structure defined on R3, e.g. the construction uses a scaler product. Cross products and scaler products depend upon the choice of Euclidean structure and are not projectively invariant. Is it just me, or does that seem a little alarming? Fly by Night (talk) 02:09, 5 February 2011 (UTC)

The article as I read it explicitly argues that the coordinates are projectively invariant despite the non-invariant setup. —David Eppstein (talk) 02:28, 5 February 2011 (UTC)
Really, maybe I missed that. Could you point me towards that? (The article doesn't contain the word invariant). Fly by Night (talk) 02:53, 5 February 2011 (UTC)
The part in the geometric intuition section about "up to a common (nonzero) scalar multiple". —David Eppstein (talk) 03:13, 5 February 2011 (UTC)

You should think of R3 is an affine coordinate patch of P3 (that is, it is just P3 minus the plane at infinity). Io describe lines in P3, it's enough to describe those in R3, and then add in the ones at infinity (e.g., take the projective closure).

That said, I'm not defending the approach taken by the article, though, which I find to be quite awkward. I think a better way to define the Plucker coordinates is to think of the space of lines in P3 as Gr(2,4). Planes through the origin in R4 are defined by simple two-forms in , which are uniquely defined up to scale, so there is a one-to-one correspondence of Gr(2,4) with the set of simple two-forms in (this is the Klein quadric). The coefficients of a 2-form in a basis then define the Plucker coordinates. The article should probably discuss this approach more explicitly. Sławomir Biały (talk) 13:00, 5 February 2011 (UTC)

Applied mathematics

Input needed at Talk:Applied mathematics, where Michael P. Barnett (talk · contribs) has proposed various re-writes of the lead paragraph of the article. My own view is that his writing style is poor, his proposed leads are rambling and do not summarise the article, and he makes several unsourced claims; in short he is proposing to replace the current brief and clear lead paragraph with a POV mini-essay. But that's just my opinion - views of other editors would be useful. Gandalf61 (talk) 10:30, 5 February 2011 (UTC)

In his comment on the talk page, Charles Matthews found a charitable tone, which is worth emulating. I was unable to find the kind words needed before editing yesterday, and so I did not explain my edits on the talk page.
Yesterday, I expanded the lead with a sentence or two describing the activity of applied mathematics, that is formulating and studying problems in other (empirical or more empirical) fields, and noting that this activity had given rise to topics in mathematics, that then became the subject of study for their own sake (in the activity of pure mathematics). My expansion failed to cite the conventional sources that my edit summary mentioned, e.g. von Neumann, Kantorovich, etc. What is important is that applied mathematics not be limited to a collection of techniques: Both the techniques and the practical activity need to be mentioned.  Kiefer.Wolfowitz  (talk) 12:24, 5 February 2011 (UTC)


The situation regarding the articles titled ABC triangulation XYZ, for various values of ABC and XYZ, seems less than satisfactory. In particular:

How much difference is there between the topics of these articles? Should some be merged? How should they link among each other? Should we have a disambiguation page titled triangulation (mathematics) that would link to these and also to triangulated category and Delaunay triangulation and upper triangular matrix (apparently "triangulation" sometimes means putting a matrix into that form)? Michael Hardy (talk) 22:25, 6 February 2011 (UTC)

The first one you list, triangulation, is completely unrelated to the rest: it's about locating objects by measurements from three other objects, and the other four are all about some sort of simplicial complex. The next three are all about similar topics (complexes where the cells are actual Euclidean triangles in the Euclidean plane) so are in that sense different from the fifth in which a triangle is something more abstract. And, although mathematically they are similar, polygon and point set triangulations are quite different from the computational point of view. But triangulation (geometry) seems kind of useless to me since it is trying to be something of a catch-all and we already have triangulation (disambiguation) for that. For the same reason I don't see a justification for creating a new triangulation (mathematics) article: how would it differ from triangulation (disambiguation)? —David Eppstein (talk) 22:59, 6 February 2011 (UTC)
It's not at all unrelated to the rest, and it's not about "locating objects by measurements from three other objects". It's about locating objects by measurements from two other objects in the simplest cases. Surveyors use triangulations of the surface of the earth; geometers speak of triangulations of the plane; the latter is merely a more abstract thing. Michael Hardy (talk) 04:30, 7 February 2011 (UTC)
Well, at the very least triangulation (mathematics) would omit the non-mathematical topics. There are several cases where XXXX (mathematics) is a disambiguation page and XXXX is also a disambiguation page, and in which this particular division of labor is clearly useful. For example partition (mathematics). Michael Hardy (talk) 23:20, 6 February 2011 (UTC)
Actually, it is desirable to have directions or distances from four or more known points to a new triangulation station. This gives one enough redundancy to isolate a gross error (if any) and make an estimate of the magnitude of minor errors. JRSpriggs (talk) 07:38, 7 February 2011 (UTC)

The Signpost interview

FP nomination

Two animations related to maze generating algorithms have been nominated for FP. See Wikipedia:Featured picture candidates/Maze Generation 2.--RDBury (talk) 08:20, 7 February 2011 (UTC)

Also, the previous nomination, WP:Featured picture candidates/Non-intermediate phases of BML Traffic Model, is about to close so please take a look if you haven't already. It does happen that pictures aren't promoted simply because there aren't enough votes.--RDBury (talk) 08:35, 7 February 2011 (UTC)

Groupoid algebra up for deletion

The brand-new article Groupoid algebra has been nominated for deletion.  --Lambiam 19:30, 7 February 2011 (UTC)

Adjoint representation disambiguation links

Greetings! This month, we have a large number of links to the disambiguation page, Adjoint representation - 61 links, to be exact. We at the Wikipedia:Disambiguation pages with links project would appreciate any help you could give us in fixing these ambiguous links. Cheers! bd2412 T 00:41, 8 February 2011 (UTC)

Shouldn't these two be merged? — Kallikanzaridtalk 22:24, 8 February 2011 (UTC)
Not necessarily. Charles Matthews (talk) 23:06, 8 February 2011 (UTC)

Gyrovector space

Project members might want to keep an eye on links that feed into gyrovector space. Someone has been trying to do quite a bit of WP:UNDUE promotion of this article, which perhaps includes some legitimate mathematics, but also appears to include some crackpot ideas. Sławomir Biały (talk) 13:32, 8 February 2011 (UTC)

Peer Review for Logarithm

I have nominated logarithm for peer review. Please talk here. Thank you all, Jakob.scholbach (talk) 21:41, 9 February 2011 (UTC)

De Groot Fourier Transform

The new article De Groot Fourier Transform has some very strange statements. E.g.,

DGFT is an method with two variables: groot and power.

I find myself doubting that "groot" is actually used as a parameter. The only reference in the article doesn't seem to talk about an analog of the Fourier transform at all.

I have the feeling that this is an elaborate hoax, but this is not a field that I'm familiar with. Can someone else take a look? Ozob (talk) 02:55, 12 February 2011 (UTC)

The referenced work is a masters thesis, Localization and Classification using an Acoustic Sensor Network, by de Groot. The Wikipedia article is pretty much a direct copy of Appendix D in the thesis (page 110), and the work is copyrighted with the notice:
All rights reserved. No part of this thesis may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior written permission of the above-mentioned.
Notability aside, it's likely a copyvio. Cheers, Ben (talk) 03:42, 12 February 2011 (UTC)
If it's a master's thesis, it was probably put there by the copyright owner, so it would not be a violation. But maybe it's OR. Michael Hardy (talk) 04:40, 12 February 2011 (UTC)
I have marked it for speedy deletion under WP:CSD#G12. In any event, even if the author did release this under the GFDL, it is still clearly original research. This at least saves time at AfD. Sławomir Biały (talk) 13:52, 12 February 2011 (UTC)

Proposal for all articles

WP has improved its math articles greatly since just 3 years ago, when reading an article on a topic one did not already know involved nested (and sometimes circular) link chasing for definitions (links that refer to articles with more links, and so on). I propose that editors try to put a WP:HAT on each article that does not define all its terms, with something like, "This article might be easier to read if you read article A first", in the case that terms come up that can best be understood by reading prerequisite article A, instead of the reader having to chase links for definitions. This might be something like a bottomless pit leading into philosophy of math, but it might also back link to an article the reader is already familiar with, breaking the "infinite" regression back. Remember what Hawking said about what the flat-earth-on-the-back-of-a-turtle-woman in the audience said to Bertrand Russell when he asked her upon what did the turtle upon which the earth rested rest, "its turtles all the way down"[26]. PPdd (talk) 05:32, 12 February 2011 (UTC)

This is a perrenial proposal. I'm against silly notes like this. They violate WP:HAT and are rarely if ever written in a tone appropriate to an encyclopedia article (they directly address the reader). Besides, they shouldn't even be necessary. A well written lead should establish the context of the article, including Wikilinks, so that readers can navigate from those. There has also been a recent proposal to increase the use of navboxes, which also serve a similar purpose. Sławomir Biały (talk) 13:15, 12 February 2011 (UTC)
I have added an FAQ entry about this one. PPdd, this proposal has come up many times before. Every time someone's found an article where this is a problem, the right fix has always been to revise the lead or some other part of the article. Ozob (talk) 15:03, 12 February 2011 (UTC)
FAQ is good (especially for late comers to here like me), but it might also specifically mention Bullet point #8 here[27] and this[28]. PPdd (talk) 15:17, 12 February 2011 (UTC)
The difficulty is that highly technical terms, in math at least, cannot be simply explained in a few words. Moreover, adding definitions of every term used quickly makes a paragraph incomprehensible, because the main point of the paragraph is lost among all the side points. (I also note that you were the one who added that section to the MOS a couple days ago [29]). Hatnotes are used for disambiguation, not for prerequisites. — Carl (CBM · talk) 15:22, 12 February 2011 (UTC)

Another related proposal regards "suggested prerequisite for more easy comprehension", which is subtly different from a "more general treatment" hat. PPdd (talk) 15:17, 12 February 2011 (UTC)

The standard way that we handle prerequisites is by judiciously linking to them in the lede section, and also by adding "introduction" or "background" sections to the article, as with Diagonal lemma. Remember that our articles are intended to be references, not detailed introductions like lecture notes. — Carl (CBM · talk) 15:26, 12 February 2011 (UTC)

help with an svg file

I keep having trouble with inkscape—could somebody please help me out with this image: Complex number illustration multiple arguments.svg? I want the black rectangle be replaced by a z and the extraneous red phi removed. Thanks! Jakob.scholbach (talk) 14:48, 12 February 2011 (UTC)

I'll take a look and see what I can do. RobHar (talk) 18:31, 12 February 2011 (UTC)
Looks like I fixed it. I deleted phi (hopefully the correct one), and converted the text to path (that's what you need to do to when some text is just showing up as a big black box; you can just select everything in inkscape and click on "Path → Object to Path" and it should work out). RobHar (talk) 18:49, 12 February 2011 (UTC)
WPM at its best—thank you! Jakob.scholbach (talk) 21:31, 12 February 2011 (UTC)

Proposal re definitions for all articles

This has likely been covered before on talk, but I propose a general suggestion to add a "Definitions" section at the bottom, for terms defined in the article, for ease of reference. An opposition to this proposal might be that a user can do a search in the article, but this likely produces numerous results (the first of which should be the definition, if a definition has been made in the article. PPdd (talk) 15:59, 12 February 2011 (UTC)

Are you proposing that every article should repeat the formal definition of all the terms it uses? That's the point of wikilinks: the first use of a term will be linked, and the reader can follow the link the get a whole article on the other topic. If we want to summarize the definition within the article, it's better to do that in the regular prose, not in some section at the bottom. We can assume that the reader will actually read the article... — Carl (CBM · talk) 16:05, 12 February 2011 (UTC)

Very often the definition of the concept that the article is about is in the first sentence or otherwise near the beginning of the article. Michael Hardy (talk) 18:26, 12 February 2011 (UTC)

Category rename

There is a proposal to rename the category Recursion theory to Computability theory that hasn't received any response yet. Please comment there if you have any thoughts on the matter.--RDBury (talk) 08:19, 13 February 2011 (UTC)

The category was renamed yesterday. — Carl (CBM · talk) 13:04, 15 February 2011 (UTC)

Fundamental solution

Comments on Talk:Fundamental solution indicate a need to explain the relationship with Green's function. This is one of those interfaces between traditional language and contemporary mathematical language that has been discussed here. That would be part of the issue only, though. Charles Matthews (talk) 12:24, 15 February 2011 (UTC)

Wikipedia talk:Make technical articles understandable

Following the promotion of rhodocene to FA status, some discussion has started again at Wikipedia talk:Make technical articles understandable. That guideline is written in a way that does allow for some technical articles, although it was written to encourage all articles to be as accessible as possible. There have been some useful conversations here recently about accessibility, and people who contributed to those may be interested in following the discussion on the guideline page. — Carl (CBM · talk) 13:00, 15 February 2011 (UTC)

Target audience in WPMath assessment template

Hey all. In looking through the discussion at Wikipedia talk:Make technical articles understandable mentioned by Carl in the previous section, in particular some comments of User:Sławomir Biały on the "target audience" of an article, I had a crazy idea: we could add a field to the Maths rating template banner we put on talk pages that holds the "target audience" of the article. It certainly seems like the target audience of an article is something that it is important to establish. Editors who have spent a long time on certain articles end up having to justify the work they've done to editors who have just shown up and are unhappy with the level of exposition. And that's fine, but it would help if the "seasoned" editors of the article had some way of pointing to an established consensus of what the "level" of the article is. I think there are several other ways this would help. The types of "levels" could be something like "Basic", "High school", "Undergraduate", "Advanced undergraduate", and "Graduate" (where the last should be used sparingly, and the specific terms used could be made more international or otherwise clarified). The approach of "one level down" that Carl has been talking about at Wikipedia talk:Make technical articles understandable would provide a guideline for how to assess the "target audience" of a given article. For some other articles, one would also want to use the subject's popularity to "lower" the level. Thoughts? RobHar (talk) 14:46, 16 February 2011 (UTC)

I don't see any reason why we, as a wikiproject, couldn't designate a "target audience" for an article. On the other hand, I am certain that some editors feel that every article should be aimed at a high-school audience (at the extreme fringe, editors sometimes argue that esoteric topics shouldn't be covered at all). So all the we could do is say, "this is what we think about it"; we can't force anyone else to listen.
A separate issue is that it takes a huge amount of work to go through and actually tag articles with this information. Let me tell you...
I have a different suggestion: any article that is marked "Top" or "High" priority should be written to be understandable by someone with no more than high school mathematics experience. "Mid" priority articles should be written so that at most freshman and junior topics are required. Articles marked "low" priority could be handled on a case by case basis. This would give an easy rule of thumb, and it uses the existing priority ratings that we have. — Carl (CBM · talk) 15:17, 16 February 2011 (UTC)
That's a pretty nice suggestion. Is there any way we could go about expressing this rule of thumb explicitly somewhere? I think that would be helpful. RobHar (talk) 15:32, 16 February 2011 (UTC)
One option would be to add it to the maths rating template. We could add a short section below the rating information that says something like this for Top/High:
And like this for Mid:
And like this for Low (if we need anything)
These could appear automatically inside the rating template based on the priority rating. — Carl (CBM · talk) 15:44, 16 February 2011 (UTC)
I like the idea of target audiences -- or at least think it's worth a shot. I strongly disagree with linking that to article importance. Some very important parts of math are esoteric, and some unimportant things are easy. CRGreathouse (t | c) 21:30, 16 February 2011 (UTC)
For example, Rhombicuboctahedron is rated Low-priority, but it should be accessible to a general audience. Homological algebra is Top-priority but probably can't be made accessible to general audiences (or even most undergrads?) in any meaningful way. The best we could hope for is a lede that could be understood by high-school students. CRGreathouse (t | c) 21:38, 16 February 2011 (UTC)
I agree with that high priority things can be more advanced, but I think that in practice our High-priority articles should also be a high priority for accessibility, even if they are advanced; list of High priority articles. Easy unimportant things are fine; I don't think that "Low" priority has any reflection on intended accessibility.
I'm not sure that Homological algebra should really be Top-priority; I would think that Topology should be Top-priority, and homological algebra should be High or Mid priority. — Carl (CBM · talk) 21:43, 16 February 2011 (UTC)
(ec)I'm a bit wary of identifying a single target audience. The background knowledge is not by any means a linear scale. Typically, the target audience will consist of a divers group of people with different types of background knowledge. For example, take any an article about Lie algebra's. Interest readers could be (advanced) undergraduate mathematics students with a fair amount formal mathematical knowledge about rings, vector spaces, etc. But they also could be interested physicists, with only very vague knowledge of formal mathematics (they probably could not reproduce the definition of a group), but with a fair amount of practical experience with some real life examples of Lie groups like SO(3), and maybe even with the concept of an "infinitesimal generator". Some engineers coming into the topic might have yet a different set of reference knowledge.
An important part of making an article accessible is to reach out to this different audiences. A danger of identifying a single target audience is that in writing the article a certain prior knowledge is assumed that is reasonable for the identified audience, but is completely unreasonable for other interested groups.
One thing I often like to do when writing technical articles is to profile a couple of different types of persons that might want to look up that article. In writing the article, I try to include things that one of these fictitious readers may have heard about (but not necessarily all of them).TR 22:08, 16 February 2011 (UTC)
Well, in both my original suggestion, and Carl's suggestion, I don't think there would be a problem with Lie algebra. In my suggestion, it would be clear (at least to me) that "Undergraduate" should be an upper bound on its level (by "undergraduate" I mean someone who has gone through say a typical freshman science program at an american/canadian university, and maybe some linear algebra). That this should be level is precisely for the reasons you cite. In Carl's scheme, since Lie algebra has high priority, in fact the suggested level would be high school background audience. More generally, with my suggestion, the argument that a given article is of interest to a diverse group of people means that its "target audience" should be a low level; and in Carl's scheme, math articles that are of interest outside of pure mathematics are typically rated high priority (in fact, that is one of the rules of thumb listed on the assessment page for rating something high). So, I'm not sure the problem you are bringing up would really show up much at all. RobHar (talk) 02:00, 17 February 2011 (UTC)
(ui) I like the idea of having some kind of "level" indicator in the maths rating tag. And I agree that while the importance is strongly correlated to the expected level, it should be used as a guideline only. One issue is that the majority of math article still don't have a rating tag at all yet. Another is that many math articles vary in what they expect the reader to know, so an article might need a different levels for different sections. However, as a baby step to see if the idea might work, how about creating a new category Category:General audience mathematics articles and adding the articles that should be readable at a high school level of math? A category like this would be incorporated into a ratings tag scheme anyway. And it won't be much time and effort lost if the idea turns out to be impractical.--RDBury (talk) 03:51, 17 February 2011 (UTC)
I was just looking at the list of Most viewed math articles to see if could be used as a starting point for the hypothetical category from the previous paragraph. A few issues occurred right off the bat. First, biography articles should probably be considered general audience without have to say so. Second, there really aren't that many articles on the list with no advanced math at all. For example Circle, which you would this is a pretty basic topic, has a section on representations in the complex plane. I certainly wouldn't throw out the section because not everyone knows what a complex number is; that information will be useful to those who do and the rest can skip the section. So it should be stressed that a general audience tag should be taken as a guarantee that someone who graduated high school will be able to understand every word.--RDBury (talk) 04:39, 17 February 2011 (UTC)

online copies of cited references

I'd appreciate if people citing math papers in WP articles could make an effort to include non-paywall links to copies of the papers when such are available. The papers are often on the authors' personal websites or preprint sites like arxiv, and at other times can be found through citeseer or by googling the title, but sometimes they can be a bit obscure. I try to add such links when I come across them, but that's just a drop in the bucket. Thanks. (talk) 01:27, 17 February 2011 (UTC)

I agree (and I try to do this when I can). Unfortunately, the trend of putting papers online is relatively recent, and most papers before the 1990s won't be available. It also seems to be less common in Europe; many European mathematicians don't have any personal website they could even think about posting papers on.
A separate issue, which I expect we will see more soon, are the "black market" scanned copies of books that can be found by appropriate google searches. I think we have to avoid these on Wikipedia, since they are almost always copyright violations. Readers who want them can probably find them anyway. — Carl (CBM · talk) 01:57, 17 February 2011 (UTC)
One issue that WP, for some good reasons, regards an on-line PDF as a less reliable source than a printed book. It is nice to have these in the External links section though.--RDBury (talk) 03:26, 17 February 2011 (UTC)
Yes, I know there are a lot of unauthorized book scans floating around and I'm not suggesting we link to those. I'm mostly talking about papers that are posted online by the author, to their own homepage or to a preprint server. Those should be usually considered presumptively authorized and authentic unless actually in dispute. Citeseer can be slightly trickier but I think it's generally ok to use those links unless there's concrete reason to think some particular link might have a problem. There are also quite a few scanned books at Project Euclid and those are also authorized as far as I know. There are a bunch of old French math papers at, and is sort of a German version of Arxiv for computer science papers. (talk) 04:51, 17 February 2011 (UTC)
As far as I know DBLP stores a lot of bibliographic information for computer science papers, but does not store the papers themselves. The other thing to watch out for here is that in some cases the free versions may have been placed online prior to journal refereeing and so may contain inaccuracies compared to the non-free versions. Or they may not, but it's not safe to blindly put a link to a free paper with the same authors/title assuming that it's automatically good. —David Eppstein (talk) 06:24, 17 February 2011 (UTC)
I think unless there's a known problem with a preprint, we should link to it, just making sure to label it as a preprint. Even if there's a known problem, we should probably (subject to reasonable judgment about the specific issue) link anyway but mention what the problem is. Again, this refers mostly to preprints where the online copy is somehow under the author's control, so if the problem was really bad, the author wouldn't have left it on the web at all.

Also, if there's not a good non-walled copy of the paper but there is a JSTOR scan, we should include that, since lots of public libraries subscribe to JSTOR while usually only academic libraries will subscribe to Springerlink and the like. JSTOR improves accessibility over journal publisher sites in that regard. (talk) 06:53, 17 February 2011 (UTC)

I agree, in the majority of the cases peer review leads only to minor corrections, which rarely effect the statements that an article is referenced for. If PR does lead to major changes, most authors also update the preprint. I don't think there is reason to be overly careful. (although if possible on should always check).TR 09:23, 17 February 2011 (UTC)
David--you're right about DBLP, it appears to be more like Citeseer in that it has links to fulltext on other sites. I was thinking of ECCC (, which has a lot of online material but is limited to complexity theory. (talk) 07:02, 17 February 2011 (UTC)
This is clearly not just an issue for WikiProject Mathematics, but is relevant to all citations to academic journal papers regardless of academic field, so this discussion should be raised/moved/flagged up somewhere more general. Wikipedia Talk:Citing sources, perhaps? Qwfp (talk) 08:03, 17 February 2011 (UTC)
I think the general practice is to link document identifiers if they are available. The "cite xxx" and "citation" templates have parameters specifically to support DOI, PubMed, and Bibcode identifiers. Other identifiers can be linked using the "id=" parameter of these templates and using templates like {{arxiv}} ,{{MR}}, {{JSTOR}} or {{Zbl}}. Using these specialized templates is preferred to using the "url=" parameter to link to any of these databases/archives.TR 09:18, 17 February 2011 (UTC)
Yes, that's what I generally do. But these link only to full-text on the official journal sites. Google Scholar often links paper titles to open-access versions when available, but I tend to look for the doi and use that in {{cite doi}}. This thread has made me consider also adding a link to the end something like [preprint], when such is available. Qwfp (talk) 10:29, 17 February 2011 (UTC)
For referencing preprints on the arxiv it is better to use "id={{arxiv}}". Note that this will link to the abstract page rather than directly to the pdf. This gives readers the choice what format they want. (usually both PS and PDF are available). Also note that only DOI links, will send you directly to the journal page, MR, JSTOR, PubMed, bibcode, etc. will provide a link to the article's entry in the respective database/repository.TR 11:30, 17 February 2011 (UTC)
True, good point, though the sites these templates link to are of use only in certain academic fields. In my particular field of medical statistics the only two of those services that are really relevant are JSTOR and PubMed, which provides open-access abstracts but only links to the official site for the full text. The other services are almost never used at present. The placing of preprints or postprints on university websites is increasingly common, however, but there's little point creating a template for these. Qwfp (talk) 11:52, 17 February 2011 (UTC)

Poincaré conjecture and accessibility

Continuing the accessibility trend of late, there is a conversation visible on my talk page [30] about Poincaré conjecture. Since this is one of the Millennium Prize problems, it really should be as readable as possible up top. I made a minimal change to the lede to point out the fact, which is well known to confuse students, that the 3-sphere is the surface bounding the 4-dimensional unit ball (rather than, say, the 3-dimensional solid from grade school geometry). My change was reverted. Maybe someone else can find a better wording? — Carl (CBM · talk) 12:31, 17 February 2011 (UTC)

Rewrite of lead at "Linear algebra"

A couple of editors are attempting to rewrite the lede at Linear algebra. I reverted the first try here (as I didn't think it was an improvement) other edits have been made since. Other views welcome. (I'm traveling all day today and unable to give much attention to this.) Paul August 11:24, 19 February 2011 (UTC)

That article is in such poor shape that we should do everything we can to encourage the energies of new editors. Almost any attention to the article would be most welcome. At present, the lead is probably not ideal, but I think it's more constructive to get people focused on expanding the article, rather than worrying over the color of the bikeshed. Sławomir Biały (talk) 13:12, 19 February 2011 (UTC)

Lists of integrals

Am I the only person on Wikipedia who is actually monitoring Lists of integrals? The page is viewed 1900 times a day and supposedly has 49 watchers. Just today, substantial vandalism was left untouched for more than 13 hours. Xanthoxyl < 02:46, 20 February 2011 (UTC)

Sorry but how can you tell how many people are watching a page? BrideOfKripkenstein (talk) 03:56, 20 February 2011 (UTC)
External tools at the top of the history. Xanthoxyl < 04:50, 20 February 2011 (UTC)

On my user page you'll see an easy way to tell how many people are watching. But I may not be watching all the pages that I'm watching. (Apologies to Yogi Berra.) Maybe Xanthoxyl is the only person monitoring that page. Being the only person watching a page has happened to me sometimes. Michael Hardy (talk) 07:35, 20 February 2011 (UTC)

Page moves and renaming


As a result of my nominating a page (Dehn plane) for deletion. Consensus was that the name was incorrect as it could not be sourced and the deletion discussion is here Wikipedia:Articles_for_deletion/Dehn_plane.

My move, based on the deletion discussion, was discussed here Talk:The_Dehn_plane#Bold_page_move

Several moves later it was left at Non-Legendrian geometry.

Now a single editor has gone against consensus and changed it back to a badly titled "The Dehn plane"

Firstly "The" should not be used, secondly consensus was against using Dehn plane and thirdly it seems as though some editors are deciding that their way is the right way even though it is against consensus.

I fully appreciate being bold, but something has to be done about this. There is no proof given so far that shows a convincing argument for using Dehn plane in any apart of the title. It has so far only produced one neologism from one source.

Chaosdruid (talk) 21:24, 20 February 2011 (UTC)

What we really need more urgently is someone fluent in German to read Dehn's paper and sort this mess out. The secondary sources are some combination of wrong, confused, and self-contradictory. (But yes, fixing the name issue is a good idea too: the standard terms for Dehn's two examples are "semi-Euclidean geometry" and "non-Legendrian geometry"). Sławomir Biały (talk) 21:33, 20 February 2011 (UTC)
I see this discussion is continuing in a new section below Wikipedia_talk:WikiProject_Mathematics#To_boldly_go_against_the_consensus Chaosdruid (talk) 19:28, 21 February 2011 (UTC)

Curve (geometry)

At best the title of this new article is confusing since it's not about Curves in the mathematical sense. I thought flexible strips used in drafting were called splines, from which the mathematical term was derived; please confirm or correct me on this. It seems like we should have an article on them, whatever they're called. We also have a rudimentary article on Elastica theory which covers a mathematical model of these things.--RDBury (talk) 01:24, 22 February 2011 (UTC)

The article as it is currently written seems to be about a particular product ("flexible curves") produced (and probably trademarked) by a company. Since the specific product clearly isn't notable, there is probably very little worth merging anywhere. I would support redirecting to curve (or deleting, since disambiguation seems unnecessary). Sławomir Biały (talk) 01:50, 22 February 2011 (UTC)
We have the article flat spline about the general notion. I went ahead and boldly redirected curve (geometry) to curve. Sławomir Biały (talk) 01:53, 22 February 2011 (UTC)

Absurdity constants, Suppes, Church, and Currie's paradox

I recall something about "absurdity constants" (not absurdity "constraints") in relations to Suppes' Logic, Methodology and Philosophy of Science, Church's thesis, and Curry's paradox, but that is all I remember. Can anyone help with this for the absurdity article? PPdd (talk) 05:39, 12 February 2011 (UTC)

I'll try to look at it next week, although I may have lent my copy to a colleague.  Kiefer.Wolfowitz  (talk) 15:01, 12 February 2011 (UTC)
I have a different book by Suppes, whose index lists no "absurdity". Sorry I couldn't help.  Kiefer.Wolfowitz  (Discussion) 17:38, 22 February 2011 (UTC)
Thanks, but note - my memory might be wrong; that is where I best recall seeing "absurdity constants". Since I was a student both of Church and Suppes, my (errant)memory might be biased. PPdd (talk) 15:20, 12 February 2011 (UTC)
There certainly appear to be a number of Google hits for "absurdity constant" in the literature. See, for example, Gabbay, Dov (2004). Handbook of the History of Logic. Amsterdam: Elsevier. p. 191. ISBN 9780444516237. , in the chapter "Paraconsistency and Dialetheism":
"For example, in both classical and intuitionist logic there is an absurdity constant, ⊥, such that for all β, ⊥ → β is a logical truth."
-- The Anome (talk) 20:20, 22 February 2011 (UTC)

Talk:Rake (angle)


I have just added the maths project banner to Talk:Rake (angle)

I think it is within your scope but would appreciate someone checking that !

Thanks Chaosdruid (talk) 02:26, 22 February 2011 (UTC)

From the edit history, it appears that this was originally about a part of motorcycles. Now it has lost that connection and appears to be merely a definition of a synonym of vertical angle (angle from the horizon) or zenith distance (angle from vertical). It needs a category, but does not appear to me to be about mathematics. In short, it is a mess. JRSpriggs (talk) 03:46, 22 February 2011 (UTC)
Am I wrong in thinking it should merged with the corresponding entry in Wiktionary?--RDBury (talk) 16:23, 22 February 2011 (UTC)
The original page is here [31] and only mentions bicycles in the second example.
I do not think it should be solely about motorcycles, that material was added afterwards, as it is clearly about more than just motorcycles. It seems crazy that there are already so many different rake pages linked from Rake.
The page was expanded (almost hijacked) until it was solely about motorcycles and then the material was moved to the bicycle and motorbike geometry page leaving the redirect. Chaosdruid (talk) 04:31, 23 February 2011 (UTC)
I think RDBury has a point. How much is there to say about this thing, beyond its definition? A definition is not enough to justify an article. --Trovatore (talk) 04:35, 23 February 2011 (UTC)
Well the main point I would make is that the angle of rake is mostly used to describe either ships prows/bows/other features and motorcyles/bicycles. I suppose this could be the page soley for ship's angle of rakes? (all the rest having their own pages rather than being wiktionaried) Chaosdruid (talk) 05:24, 23 February 2011 (UTC)
It just doesn't sound like there's enough there for an article. --Trovatore (talk) 09:42, 23 February 2011 (UTC)

Existential theory of the reals

Existential theory of the reals is an orphaned article: nothing links to it (except the list of mathematics articles). Some links to it could be created and it would bear expansion.

It's in three categories (maybe others should be added?): Category:Real algebraic geometry, Category:Mathematical logic, Category:Computational complexity theory. Michael Hardy (talk) 16:54, 23 February 2011 (UTC)

Potential merge to semialgebraic set. Charles Matthews (talk) 18:06, 23 February 2011 (UTC)
It's a very important topic in the computational complexity theory of real-number computation. I don't think that merge would do that aspect of the subject justice. On the other hand, the existing article is in bad shape. —David Eppstein (talk) 18:22, 23 February 2011 (UTC)
It was in even worse shape before I edited it. (I think?) Michael Hardy (talk) 23:00, 23 February 2011 (UTC)
I was thinking of linking it to "elementary theory of the real numbers" but I discovered we have no such article! Moreover, elementary theory is rather monosyllabic. It would be helpful to fill these gaps if anyone gets a chance. Tkuvho (talk) 14:32, 24 February 2011 (UTC)
The elementary theory of the real field is the theory of real closed fields. Algebraist 18:56, 24 February 2011 (UTC)
Ah, thanks. Should there be a redirect from Elementary theory of the reals? Apparently elementary theory should be connected to real closed field then. Tkuvho (talk) 20:15, 24 February 2011 (UTC)

Directing it to "elementary" rather than "existential" doesn't seem to make sense, since that's an essentially different problem. It's about sentences that begin only with existential quantifiers, and one can imagine statements like the one about NP-completeness changing if one allowed universal quantifiers. Michael Hardy (talk) 00:48, 25 February 2011 (UTC)

I didn't mean that "existential" should be redirected to "elementary", but rather that there should be an extra redirect to real closed field from elementary theory of the reals, as well as a "see also" cite of elementary theory of the reals at existential theory of the reals. Tkuvho (talk) 06:06, 25 February 2011 (UTC)
What would be the point of a see-also link that is redirected to an article already prominently linked from the first sentence of existential theory of the reals? —David Eppstein (talk) 06:21, 25 February 2011 (UTC)
I see the link was added two days ago. Thanks for pointing this out. Tkuvho (talk) 08:26, 25 February 2011 (UTC)

Singular value decomposition is up for review

The article singular value decomposition is up for A-class review. It needs both reviewers and editors. Sławomir Biały (talk) 14:14, 24 February 2011 (UTC)

To boldly go against the consensus

The page Dehn plane contains a discussion of an example of a plane where the parallel postulate fails. The example satisfies Legendre's theorem to the effect that the sum of the angles in a triangle is π. The page has now been moved back to non-Legendrian geometry, even though the geometry discussed here is eminently Legendrian. This is the kind of committee decision we are getting famous for. Tkuvho (talk) 12:42, 21 February 2011 (UTC)

What is most troubling is how unreliable the content there should be regarded. The naming issue should be a totally peripheral matter. Sławomir Biały (talk) 12:48, 21 February 2011 (UTC)
The current content is reliable. Tkuvho (talk) 13:55, 21 February 2011 (UTC)
Boldly going against the consensus? No, that is not how wikipedia works. We make bold edits, they are discussed and consensus is formed.
To make a "bold edit against consensus" means that the editor believes that consensus does not matter.
It would be better to have read the talk pages and deletions discussions which were available on the talk page, not yet archived, and then start more discussions that to simply ignore the consensus that had previously been achieved. Chaosdruid (talk) 19:31, 21 February 2011 (UTC)
Although Tkuvho feels confident that the article's contents are reliable, I still feel like better verification is desirable. I think more discussion and better sources would help, rather than continuing to argue over the title. Present day sources that include "semi-Euclidean geometry" and "non-Legendrian geometry" might be good places to attempt to verify the article's content, as well as to write a better article. Also sources discussing "non-Archimedean geometry" can be used with some care. Sławomir Biały (talk) 19:36, 21 February 2011 (UTC)
In the mean time, I suggest that the article be moved back to Semi-Euclidean geometry as a reasonable compromise until the article actually gets sorted out. Unfortunately, admin powers seem to be required to do this now. Sławomir Biały (talk) 19:46, 21 February 2011 (UTC)
Yup, the last page move created lots of problems with double redirects and so forth. It is likely that the page couldn't be put back to "Dehn plane" for those very reasons also. Chaosdruid (talk) 19:58, 21 February 2011 (UTC)
(ui) For a little context, the article recently survived an AfD here. This is a good topic for an article but what we have at the moment needs much work or perhaps a restart from scratch. Hilbert gives a long discussion of the Archemedian axiom in geometry and it's relationship to the parallel postulate and the sum of angles in a triangle, citing Dehn's paper. It appears however that "Dehn plane" plane is a noelogism, or at least not notable as a phrase. There also seems to be some confusion on the term non-Archemedian, as used in modern English, and non-Legendrian as used in 19th century German, I think it will take someone reasonably fluent in the latter to determine what Dehn actually meant since mathematical language changes significantly over a hundred years. So it may well be that the geometry is "Legendrian" in the modern sense but not what Dehn meant. I personally think the article should be moved to Non-Archimedean geometry which is definitely not a neologism, see the Springer EoM entry for example.--RDBury (talk) 23:40, 21 February 2011 (UTC)
Hi RD, thanks for your interest. The AfD discussion you mentioned is based on the false premise that the example discussed here is non-Legendrian. The error resulted from the conflation of two examples discussed by Dehn, as I explained a week ago in detail at Talk:Dehn plane. The property of being non-Legendrian has nothing to do with the property of being non-Archimedean. Both terms have been stable since at least Dehn's time. The point of Dehn's example was not that the geometry is non-Archimedean (the existence of such geometries is much older), but rather that it violates the parallel postulate. Moving this to "non-Archimedean geometry" makes no sense. Tkuvho (talk) 03:08, 22 February 2011 (UTC)
Thanks for the clarification, maybe a new article is in order then.--RDBury (talk) 16:30, 22 February 2011 (UTC)
One immediate problem is that the contents of the page do not correspond to its current title, but (literally) on the contrary. Can we have a consensus for moving this to "Dehn's plane" or "dehn's counterexample"? Tkuvho (talk) 17:13, 22 February 2011 (UTC)
There are still problems with the double redirects caused by the page moves, the bots are possibly getting confused. I have asked Tkuvho to take a look at them as he was the last to move. Chaosdruid (talk) 16:18, 25 February 2011 (UTC)

New disambiguation

The new article Sum of squares (disambiguation) includes a number of maths topics and hence might be worth checking. Melcombe (talk) 17:27, 25 February 2011 (UTC)

Wijsman's decomposition

I just needed a beautiful theorem which lots of people know but is not written down anywhere (asfaik) in an accessible way including elementary examples. Suppose a probability space is invariant under a compact group of transformations on . Suppose for simplicity that only the trivial subgroup leaves all elements of the space fixed (otherwise we must divide it out). Assume smoothness. Then the space is essentially the product of two independent probability spaces: one space carrying the maximal invariant, the other being the group itself with Haar measure. There is a neat elementary example in the Monty Hall problem.

The result is also much used in ergodic theory, it's called the ergodic decomposition.

Question: what to call it, what to link it to? I'd like to start writing the article but I'm a mathematical statistician, not an analyst or ergodic theorist or whatever.

There are connections to sufficiency, to invariance (in statistics), to experimental design, and so on. Everywhere where symmetry can be used to simplify statistical models or statistical reasoning. Multivariate normal distribution and multivariate analysis.


R. Wijsman (1990), Invariant measure on groups and their use in statistics

P. Diaconis (1988), Group representations and their applications in statistics and probability

Richard Gill (talk) 15:54, 22 February 2011 (UTC)

Maybe ergodic decomposition is a suitable name for it. Or Wijsman's decomposition? Can you clarify what you mean by "carrying the maximal invariant", and can you tell us a few concrete examples? Those might actually shed some light on what it should be called and which other articles should link to it. Michael Hardy (talk) 23:45, 26 February 2011 (UTC)

Graphical comparison of musical scales and mathematical progressions AfD

The above article is up for AfD here. I've had my say but there is some new discussion basically asking for more expert opinions, so please have your say if you can bring some mathematical expertise to the issue.--RDBury (talk) 21:49, 26 February 2011 (UTC)

R. Catesby Taliaferro

R. Catesby Taliaferro is a stubby new article, doubtless imperfect. Do what you can. Michael Hardy (talk) 00:49, 27 February 2011 (UTC)

Any idea whether he pronounced it "Tolliver"? That's the usual pronunciation from the Southern US, but Yankees usually don't know that, to say nothing of folks from other countries. But I wouldn't want to add that unless we can find out. --Trovatore (talk) 00:56, 27 February 2011 (UTC)

The infamous MHP problem ended up in arbitration

After constant editing conflicts for years, a discussion archive probably running several volumes as printed books and 2 failed mediations the article has ended up in arbitration now.

Maybe it is of interest for some of the editors here or they even want to provide an assessment/opinion.

Wikipedia:Arbitration/Requests/Case/Monty Hall problem

--Kmhkmh (talk) 22:06, 20 February 2011 (UTC)

It is probably useful to point out that Arbcom has historically avoided making decisions about the content of articles; they only deal with editor conduct. The actual disagreements about the content have to be handled on the article's talk page. — Carl (CBM · talk) 22:44, 20 February 2011 (UTC)
yes, they emphasized already that they intend to focus on potential misbehaviour of editors rather than content issues. However most involved parties are already arguing content nevertheless and there are content issues at the core of various long standing conflicts between authors.
Another thing that might be advisable is reevaluate the article's excellence status after the arbitration is completed, since the article has changed rather significantly (not necessarily for the worse though).--Kmhkmh (talk) 00:27, 21 February 2011 (UTC)
Please see the hilarious preliminary statement by Alanyst!  Kiefer.Wolfowitz  (Discussion) 19:54, 21 February 2011 (UTC)
Alanyst almost cost me a mouthful of coffee and a new keyboard. Gandalf61 (talk) 16:08, 28 February 2011 (UTC)

Categorical bridge

Categorical bridge has been prodded. Michael Hardy (talk) 04:33, 21 February 2011 (UTC)

I couldn't find any sources for it, so deleted it. Dreadstar 00:00, 1 March 2011 (UTC)

Boolean logic

Would someone please monitor. I'm at 3RR, and I can't say the edits I'm reverting are vandalism, just completely, and obviously, inappropriate. — Arthur Rubin (talk) 16:05, 27 February 2011 (UTC)

MTAA discusion

There is a discussion underway at Wt:MTAA that concerns this project. Sławomir Biały (talk) 17:46, 28 February 2011 (UTC)

Mar 2011

Anti-geometric mean and anti-harmonic mean needs rescuing

The new article Anti geometric mean and anti harmonic mean has been proposed for deletion for a lack of sources. This article needs rescuing. These two means are legitimate: one of them is the same as the contraharmonic mean. Sławomir Biały (talk) 14:02, 28 February 2011 (UTC)

They may be means within the meaning of that word, but are they notable? Also the article should explain how to generalize them to three or more inputs. JRSpriggs (talk) 15:20, 28 February 2011 (UTC)
At least the contraharmonic mean/antiharmonic mean is notable (there are many google scholar and google books hits for both of these terms). Perhaps an alternative to deletion is to redirect to the contraharmonic mean article. Sławomir Biały (talk) 15:34, 28 February 2011 (UTC)
The means may be legitimate, but the notability, names, and the connection between them don't seem to be. They appear to be taken from , the October 16 entry in a "riddle" blog.
The anti-geometric mean is a mean, as it's
(oops, how do you strikeout within a formula}
for an appropriate value of F. — Arthur Rubin (talk) 15:50, 28 February 2011 (UTC)
which is the Lehmer mean with p=3/2. — Arthur Rubin (talk) 15:58, 28 February 2011 (UTC)
The article is fairly clearly OR; note where it says "copyright shrenuj 2010" in the title of the blog entry that Arthur linked to, and see the username of the Wikipedia article creator. Having said that, "anti-harmonic mean" seems to be used elsewhere as a synonym for the contraharmonic mean, so this term (on its own) could merit a redirect. Gandalf61 (talk) 15:55, 28 February 2011 (UTC)
As an aside, should we make a note as to the generalized Lehmer mean,
Arthur Rubin (talk) 16:56, 28 February 2011 (UTC)

I've fixed the punctuation in the article's title. Michael Hardy (talk) 23:21, 1 March 2011 (UTC)

Multilinear subspace learning

Someone has been adding sections on and links to something called multilinear subspace learning to a variety of articles on linear algebra and multilinear algebra. I have removed one such section from the tensor article since it obviously didn't belong where it was. I'm wondering whether the rest of the added content is worth keeping though. There seem to have been only a handful of papers] published (in fairly obscure places) on this topic, most of them in the past few years and mostly by the same group of authors. What should we do about this, if anything? Sławomir Biały (talk) 11:53, 1 March 2011 (UTC)

Proposing deletion, and tagging, although I believe the SIAM journal to be legitimate. I believe most of the references should be weeded out, but I suspect that, as long as the article is here, it should be linked somewhere in multilinear algebra. — Arthur Rubin (talk) 16:14, 1 March 2011 (UTC)

Perfect number articles

Jurvetson2 (talk · contribs) has created articles 33550336 and 8589869056. As far as I can see, the only interesting property of these numbers is that they are perfect numbers, so I don't think they meet the criteria for notability of specific individual numbers at WP:NUMBER. Speedy deletion was proposed for one article, but declined. I have noted my concerns on Jurvetson2's talk page. Should we take these articles to AfD ? Gandalf61 (talk) 09:32, 1 March 2011 (UTC)

I think they should be deleted. — Arthur Rubin (talk) 10:11, 1 March 2011 (UTC)
Yes I feel like imitating the Cybermen and saying to the article 'You are deficient, you will be deleted. deleted'. I seem to be wanting to delete things quite often nowadays even though I try to find something useful about them and leave them time to grow. Dmcq (talk) 11:44, 1 March 2011 (UTC)
Both articles now taken to AfD - thank you, Arthur. Discussion is at Wikipedia:Articles for deletion/33550336. Gandalf61 (talk) 09:03, 2 March 2011 (UTC)
@Gandalf61: Thanks. It wasn't easy to do the AfD multi.
@Dmcq: They're not deficient, they're perfect. LOL — Arthur Rubin (talk) 09:12, 2 March 2011 (UTC)
Aargh! I am deficient. If I were a Cyberman my head would explode! :) Dmcq (talk) 13:05, 2 March 2011 (UTC)

k-Poincaré disambiguation

I've just saved the Kappa-Poincaré page from speedy deletion for the time being, but it definitely needs to be changed into something else, either be deleted (Wikipedia's search does seem to find all the k- K- and κ- variations already) or converted into a disambiguation page or a redirect. I'm not conversant in math issues, so I need to ask a question: Is there some particular reason that both the K-Poincaré algebra and K-Poincaré_group articles shouldn't be merged into subsections of the Poincaré group article followed by the creation of redirects for the various k- kappa- κ- -algebra -group variant names to that article? Alternatively, how about an article for k-Poincaré with the -algebra and -group versions as subsections. Because I don't understand the math or the significance of the math, I'm clueless but I'm sure one of you do. Best regards, TRANSPORTERMAN (TALK) 16:38, 1 March 2011 (UTC)

K-Poincaré algebra and K-Poincaré_group can probably be safely merged, since they are basically two sides of the same coin. Explaining what these objects are may in fact be easier if they are in the same article. However, I don't it such a good idea to merge with Poincaré group, which a much simpler and widely known object, that needs an accessible article. (The Poincaré group article should however mention at some point that it can be deformed into the K-Poincaré_group.)TR 14:41, 2 March 2011 (UTC)

Chain rule

The article titled chain rule currently says:

The chain rule is frequently expressed in Leibniz notation. Suppose that u = g(x) and y = f(u). Then the chain rule is
This is often abbreviated as
However, this formula does not specify where each of these derivatives is to be evaluated, which is necessary to make a complete and correct statement of the theorem.

Does this last form really fail to "specify where each of these derivatives is to be evaluated"? It seems to me that the first form above clutters things in such a way as to interfere with understanding, and that the second, read correctly, doesn't really fail to do anything that should be done.

Opinions? Michael Hardy (talk) 23:04, 1 March 2011 (UTC)

I'm with you on this one. The sentence isn't really Wikipedia-appropriate, anyway -- at best that's textbook language. CRGreathouse (t | c) 01:47, 2 March 2011 (UTC)
Well, since I'm the one who wrote that sentence, I think I should defend it. But I'm going to do so on Talk:Chain rule, not here. Ozob (talk) 01:49, 2 March 2011 (UTC)

Just out of interest why is chain rule marked as "mid priority"?TR 09:20, 2 March 2011 (UTC)

Help needed

There appear to be a series of disputes with Optimering (talk · contribs). One is listed at Talk:Algorithm. Another is at WP:COIN#Optimering and is mostly about an edit war at Luus–Jaakola. The assumption is that the user is the person whose work the user keeps citing, thus making WP:SELFCITE relevant. As Optimering has announced a preference to deal only with people who are also mathematical experts, I was hoping that some of you would please look at these disputes and see if you can help resolve them. WhatamIdoing (talk) 17:02, 28 February 2011 (UTC)

@WhatamIdoing, your suggested reading for Optimering seems to have been read as an endorsement of his behavior, rather than a spur to reflection (on the WP dynamics of expert editing).  Kiefer.Wolfowitz  (Discussion) 03:26, 4 March 2011 (UTC)
Also see the threads at my talk. So far I've only seen this editor write in a neutral way. He is obviously watched with some scepticism. By some in a healthy way, but by others in a fashion that borders on harassment. It would be a pity if an editor capable of writing is a niche area got scared away. —Ruud 00:52, 1 March 2011 (UTC)
Alas, Optimering's use of sources and apparent OR (in ... trying ... to document notability of the thesis) is far from neutral. Lately, Ruud has insulted MrOllie on his talk page, and similar insults to Mr Ollie by Optimering appear on the article talk page.  Kiefer.Wolfowitz  (Discussion) 03:23, 4 March 2011 (UTC)

G. J. Toomer

I just created a new article titled G. J. Toomer. Quite a large number of articles link to it, but it's very stubby. Do what you can to improve it. Michael Hardy (talk) 00:22, 4 March 2011 (UTC)


Hello, I saw on the discussion page of C*-algebra that this WikiProject supports the page. Is there anyone here who knows of references to support the statements found in the "Some history: B*-algebras and C*-algebras" section (that I have recently added 'fact' tags to)? Any help would be appreciated. (talk) 11:45, 28 February 2011 (UTC)

I've added cites (with links) to a supporting reference to the the article. Paul August 12:25, 28 February 2011 (UTC)
On a maybe related note, that page could use some attention from the C*-folks here. Mct mht (talk) 11:15, 5 March 2011 (UTC)

Archimedean property

Should Archimedean property and non-Archimedean ordered field get merged? Michael Hardy (talk) 21:42, 5 March 2011 (UTC)

Merge Archimedean with non-Archimedean? Cute, let's merge p-adic numbers with ordered field at next step. Incnis Mrsi (talk) 22:04, 5 March 2011 (UTC)
Very funny. Archimedean property is about a property; it needs to give both examples of cases where the property holds and examples of cases where it fails. Michael Hardy (talk) 23:14, 5 March 2011 (UTC)
More seriously. There are many non-Archimedean fields, some of which are ordered, but so notable as p-adic numbers are not. Imagine a redirect from "non-Archimedean ordered field" to a mess of examples and counterexamples resulting in all 4 possible flavours (because there are also Archimedean normed, but unordered, fields such as complex numbers). Incnis Mrsi (talk) 23:25, 5 March 2011 (UTC)
Non-Archimedean ordered field could be enriched by some history, which is certainly rich. Tkuvho (talk) 07:43, 6 March 2011 (UTC)

No free lunch theorem, help from probability & algorithmic analysts

This article needs scrutiny:

"no free lunch theorems... 'state[s] that any two optimization algorithms are equivalent when their performance is averaged across all possible problems.'" (The probability measure on all possible problems would be an interesting object, I assume.)

There is a related article,No free lunch in search and optimization, which cites an article by the well-known computer scientist Wegener, which probably can be salvaged.  Kiefer.Wolfowitz  (Discussion) 14:04, 5 March 2011 (UTC)

There is nothing problematic about considering probability measures an all possible problems of a fixed size. And "any two optimization algorithms are equivalent" is too strong a statement — one algorithm might perform redundant work compared to another — but I think it's safe to say that in this problem setting no algorithm is better than a brute force search. —David Eppstein (talk) 17:06, 5 March 2011 (UTC)
The statement seems completely reasonable in the context of No free lunch in search and optimization. The two articles have a lot of overlap, and it might be better to merge them. Ozob (talk) 18:40, 5 March 2011 (UTC)
Whether an algorithm is optimizing (or not) depends (in part) on which probability measure one uses on the space of possible problems. No algorithm is optimizing for all such measures. That is the point. JRSpriggs (talk) 20:40, 6 March 2011 (UTC)


I'm not sure it's the right board to post it on, but the article axiom caught my eye. AFAIK the notion of axiom being self-evident truth is very outdated: even when talking about logical axioms as described in the article, we cannot treat them as 'self-evident truths', if only because there are several logics (e.g. classical, intuitionist) that use different axioms, so calling them self-evident seems moot.

Is there anything that can be done to improve the article? I'm a complete layman in logic, so I didn't edit it myself. — Kallikanzaridtalk —Preceding undated comment added 13:13, 6 March 2011 (UTC).

I don't see the problem. It distinguishes between the traditional use and the current use in mathematics quite clearly in the lead as far as I can see. Dmcq (talk) 15:20, 6 March 2011 (UTC)

The "traditional" sense of the word makes sense in certain contexts other than mathematics. For example, in epistemology. To say it's outdated is to limit one's world-view to mathematics and forget that other subjects exist. Michael Hardy (talk) 19:26, 6 March 2011 (UTC)

This began with Euclid's Elements which distinguishes between axioms (obvious and general premises) and postulates (premises which are specific to geometry and not quite so obvious). Most of us use those two words as synonyms today. JRSpriggs (talk) 20:54, 6 March 2011 (UTC)

"Number theory"?

Our article titled Basel problem currently begins like this:

The Basel problem is a famous problem in number theory, first posed by Pietro Mengoli in 1644, and solved by Leonhard Euler in 1735.
[snip snip......]
The Basel problem asks for the precise summation of the reciprocals of the squares of the natural numbers, i.e. the precise sum of the infinite series:

Should we change "number theory" to "analysis", or to something else, or should we just delete it? Or let it stand? Michael Hardy (talk) 19:24, 6 March 2011 (UTC)

I WP:BOLDly changed it to mathematical analysis, but if someone else wants to change it again I won't object. We shouldn't just delete it because we need some context to tell readers it's about mathematics. —David Eppstein (talk) 19:30, 6 March 2011 (UTC)
Is it worth mentioning in that article that the reciprocal of that sum is the asymptotic probability that a pair of integers, selected at random, are relatively prime? (As with any special value of the Riemann zeta function.) From this perspective, number theory seems like the right categorization. Sławomir Biały (talk) 19:42, 6 March 2011 (UTC)
Certainly that's worth mentioning in the article. Michael Hardy (talk) 04:24, 7 March 2011 (UTC)
Does anyone have any idea how Mengoli and Euler thought of this problem? Tkuvho (talk) 20:16, 6 March 2011 (UTC)
Simple solution: Put both. I left analysis first as it has claim to be 'senior' here. CRGreathouse (t | c) 18:43, 8 March 2011 (UTC)

I've changed it to read thus:

The Basel problem is a famous problem in mathematical analysis with relevance to number theory, first posed by Pietro Mengoli in 1644, and solved by Leonhard Euler in 1735.

Michael Hardy (talk) 03:49, 10 March 2011 (UTC)

Citation templates now support more identifiers

Recent changes were made to citations templates (such as {{citation}}, {{cite journal}}, {{cite web}}...). In addition to what was previously supported (bibcode, doi, jstor, isbn, ...), templates now support arXiv, ASIN, JFM, LCCN, MR, OL, OSTI, RFC, SSRN and Zbl. Before, you needed to place |id={{arxiv|0123.4567}} (or worse |url=, now you can simply use |arxiv=0123.4567, likewise for |id={{JSTOR|0123456789}} and |url=|jstor=0123456789.

The full list of supported identifiers is given here (with dummy values):

  • {{cite journal |author=John Smith |year=2000 |title=How to Put Things into Other Things |journal=Journal of Foobar |volume=1 |issue=2 |pages=3–4 |arxiv=0123456789 |asin=0123456789 |bibcode=0123456789 |doi=0123456789 |jfm=0123456789 |jstor=0123456789 |lccn=0123456789 |isbn=0123456789 |issn=0123456789 |mr=0123456789 |oclc=0123456789 |ol=0123456789 |osti=0123456789 |rfc=0123456789 |pmc=0123456789 |pmid=0123456789 |ssrn=0123456789 |zbl=0123456789 |id={{para|id|____}} }}

Obviously not all citations needs all parameters, but this streamlines the most popular ones and gives both better metadata and better appearances when printed. Headbomb {talk / contribs / physics / books} 03:05, 8 March 2011 (UTC)

GREAT! This update shall increase the consistency of citations, e.g. the ordering of JSTOR and MR.
It seems that if I want to have two ISBNs, I can use "isbn= " for one (e.g., 13-digit), and then use "id=ISBN 0123456789" for the second. Unfortunately, math-reviews can then split the isbns: For example
Molchanov, Ilya (2005). Theory of random sets. Probability and its applications. Springer-Verlag London Ltd. pp. 194–240. ISBN 978-185223-892-3 Check |isbn= value: checksum (help). MR 2132405. doi:10.1007/1-84628-150-4. ISBN 1-85233-892-X.  Unknown parameter |address= ignored (|location= suggested) (help)
I would prefer to be able to use 1-3 isbns: isbn=,isbn-10=, isbn-13=, simultaneously. Thanks!  Kiefer.Wolfowitz  (Discussion) 18:15, 8 March 2011 (UTC)
With ISBNs, there's actually a trick (it only works for ISBNs however), |isbn=0123456789 translate into a raw "ISBN 0123456789", which is linked via the software rather than being linked through the template. So this means you can use |isbn=0123456789, ISBN 0987654321 Parameter error in {{isbn}}: Invalid ISBN., ISBN 1029384756 Parameter error in {{isbn}}: Invalid ISBN. and it will be converted to Bob's Book. ISBN [[Special:BookSources/0123456789, ISBN 0987654321 Parameter error in {{isbn}}: Invalid ISBN., ISBN 1029384756 Parameter error in {{isbn}}: Invalid ISBN.|0123456789, [[International Standard Book Number|ISBN]]&nbsp;[[Special:BookSources/0987654321 |0987654321]]<span class="error">&nbsp;Parameter error in &#123;&#123;[[Template:isbn|isbn]]&#125;&#125;: Invalid [[ISBN]].</span>, [[International Standard Book Number|ISBN]]&nbsp;[[Special:BookSources/1029384756 |1029384756]]<span class="error">&nbsp;Parameter error in &#123;&#123;[[Template:isbn|isbn]]&#125;&#125;: Invalid [[ISBN]].</span>]] Check |isbn= value: invalid character (help). . Headbomb {talk / contribs / physics / books} 18:41, 8 March 2011 (UTC)
I tried this technique but the ISBNs have disappeared:  Kiefer.Wolfowitz  (Discussion) 19:32, 8 March 2011 (UTC)
Molchanov, Ilya (2005). Theory of random sets. Probability and its applications. Springer-Verlag London Ltd. MR 2132405. doi:10.1007/1-84628-150-4.  Text "|isbn=9781852238923, ISBN 185233892X

" ignored (help); Unknown parameter |address= ignored (|location= suggested) (help)

Try not using the span; that was just to show you what the wikiformatting should look like. Without the span, it's: Molchanov, Ilya (2005). Theory of random sets. Probability and its applications. Springer-Verlag London Ltd. ISBN [[Special:BookSources/9781852238923, ISBN 185233892X|9781852238923, [[International Standard Book Number|ISBN]]&nbsp;[[Special:BookSources/185233892X |185233892X]]]] Check |isbn= value: invalid character (help). MR 2132405. doi:10.1007/1-84628-150-4.  Unknown parameter |address= ignored (|location= suggested) (help)David Eppstein (talk) 20:57, 8 March 2011 (UTC)
Semper Benignus! THANKS!
That was much easier Kiefer.Wolfowitz  (Discussion) 21:25, 8 March 2011 (UTC)

Wikipedia:Articles for deletion/Timelike topological feature

This pretends to be a piece of theory of Lorentzian manifolds, but… it is a theory of doubtful notability. Incnis Mrsi (talk) 09:18, 9 March 2011 (UTC)

Ptolemy's table of chords

I've created Ptolemy's table of chords, in its present form an imperfect article. Work on it! Michael Hardy (talk) 23:12, 10 March 2011 (UTC)

At Talk:Ptolemy's table of chords, I've created a "to do" list of work that should get done on this article. I'll probably get to most or all of it eventually unless others get there first. Michael Hardy (talk) 00:09, 12 March 2011 (UTC)
Here's the list:
Work that needs to be done on this article:
  • Further inline citations, including:
  • It was the earliest trigonometric table extensive enough for many practical purposes, including those of astronomy
  • (an earlier table of chords by Hipparchus gave chords only for arcs that were multiples of 7½°).
  • Several centuries passed before more extensive trigonometric tables were created.
  • Page numbers in Glowatzki and Göttsche?
  • The parts about the three distinct methods of computing chords.
  • More on the geometric theorems: Their precise statements, how they are proved, how they are used in deriving trigonometric identities, how those identities are used in computing chords.
  • History of editions of the book including those in Arabic.
  • When did more extensive tables supersede this one? Which century?
  • How did the table influence later work?
  • And probably other things.........
Michael Hardy (talk) 00:16, 12 March 2011 (UTC)

Please review seriousness v. proposed deletion as parody of new article Names of small numbers at Wikipedia:Articles for deletion/Names of small numbers

Mathematics WikiProject members, please, this is being discussed at:

Wikipedia:Articles for deletion/Names of small numbers

Thank you. Pandelver (talk) 00:05, 12 March 2011 (UTC)

May be of remote interest

There's a math-related arbcom case in which someone has proposed something along the lines that discussing math on talk pages without references or (lord forbid) pointing out an error in a WP:RS is a blockable offense (after warning, of course). Linky here. Tijfo098 (talk) 07:22, 12 March 2011 (UTC)

Is not this absurdity restricted to Talk:Monty Hall problem? JRSpriggs (talk) 10:06, 12 March 2011 (UTC)

Invitation to comment on RFC regarding the stubbing (deletion) of the Mathematics in medieval Islam article

You are invited to comment on the content dispute regarding the stubbing of the Mathematics in medieval Islam article Thank You -Aquib (talk) 04:11, 14 March 2011 (UTC)

Whew! I've certainly had problems with some rather industrious people making unjustified claims about Islamic maths with citations that don't quite back them up and bending things like turning Persian into Islamic. This seems a very drastic step though and rather a pity. I hope it all gets fixed up soon again but my experience does indicate that all claims will need to have the citations examined. Dmcq (talk) 13:25, 14 March 2011 (UTC)

Numerical approximations of π -> Approximations of π

Please see Talk:Numerical_approximations_of_π#Requested_move. Cheers, Ben (talk) 11:52, 16 March 2011 (UTC).


The usage of {{pi}} is under discussion, see Template talk: pi . (talk) 13:40, 18 March 2011 (UTC)

Quarter squares

Another editor is insisting on adding their bit on calculating quarter squares to Multiplication algorithm and I'm failing to get them to desist, latest round at Talk:Multiplication_algorithm#Construction_of_tables. ANyone like to have a look at it thanks? Dmcq (talk) 13:11, 20 March 2011 (UTC)


There are many used notations for cardinal numbers and cardinality. In all (advanced) mathematical articles which use them, we need to clarify whether the axiom of choice is assumed, and whether the von Neumann cardinal assignment and/or the assumption that cn(cn(X))=cn(X) (i.e. that "the" cardinal number of a set has the same cardinality as the set) is made. The "Union" of cardinal numbers requires some assumption similar to the von Neumann cardinal assignment, and the Sum or Product of an infinite set of cardinal numbers requires some version of the Axiom of Choice to define.

I would like to have a centralized discussion on this, putting pointers on all the articles which refer to "cardinality". I was also thinking that merging initial ordinal with aleph number might be a good start. The constructions are the same, but the assumptions are different. — Arthur Rubin (talk) 23:20, 20 March 2011 (UTC)

Unfortunately, my reference library is not available (i.e., I didn't keep it from my last move), so I would be forced to reference the material to my and my parents' books and papers. This is generally considered improper. Any ideas? — Arthur Rubin (talk) 23:21, 20 March 2011 (UTC)

I would not merge those two, no. I think aleph number is an appropriate title for a brief, and not extremely mathematical, article of fairly limited scope, namely just to tell people what these funny , , thingies that they may have seen somewhere are. For deeper information, readers should be directed to articles like cardinality. --Trovatore (talk) 00:00, 21 March 2011 (UTC)

I can see your point. In that interpretation, I couldn't help rewrite aleph number, but much of the material now in aleph number is in initial ordinal and should not remain in aleph number.
I wonder if someone can describe the difference between cardinality and cardinal number, also. Should those be divided in a similar way, with cardinality being non-mathematical, and cardinal number being more mathematical? — Arthur Rubin (talk) 00:18, 21 March 2011 (UTC)
At first thought it seems plausible to me to merge cardinal number into cardinality. I suppose cardinal number could be used as meaning "some complete invariant for cardinality, with the exact invariant depending on what scheme you have in mind" but I don't know that that is particularly standard. --Trovatore (talk) 00:25, 21 March 2011 (UTC)

@Arthur: Personally, I am not very worried about the (potential) conflict of interest. The articles we are talking about are on completely established subjects, and the books by H. and J. Rubin are mainstream, not fringe sources in any way. There are plenty of other editors who watch the articles and can edit them to add other references. Your identity is known, and you are a long-time contributor to the project. Given those facts I think you should not be too worried about editing the articles, and I will say that again if anyone raises the issue. — Carl (CBM · talk) 00:29, 21 March 2011 (UTC)

Square bracket in a link

I was thinking about puttting in a link to interval (mathematics) for things like (−π, π] because people keep 'correcting' it to two round brackets. However there is a little problem in that one then gets three right square brackets or else one has to put in a space or the right bracket is black as in (−π, π]. Any ideas on a good way of getting it looking right thanks? Dmcq (talk)

Create a set of templates {{left half-open interval}}, {{right half-open interval}}, etc. Makes it more difficult to "correct" them (and more obvious why they shouldn't be). —Ruud 16:07, 14 March 2011 (UTC)
well you could always use as long as you're not to picking about Latex within a text block.--Kmhkmh (talk) 16:10, 14 March 2011 (UTC)
Use <nowiki> tags, or any other delimiters: (−π, π] Nageh (talk) 16:20, 14 March 2011 (UTC)
Thanks everybody. I think I'll go with the nowiki or perhaps nobreak so I don't even need the &nbsp; Dmcq (talk) 16:41, 14 March 2011 (UTC)
Just been thinking about the templates left half-open interval etc. It does have the advantage it can be used for later instances that shouldn't be linked. Dmcq (talk) 17:18, 14 March 2011 (UTC)

We had this discussion a while ago (in 2003 or so?) and one of the things that got decided was that the brackets in asymmetric intervals should be enclosed within "nowiki" tags. Has that been neglected lately? Michael Hardy (talk) 17:22, 14 March 2011 (UTC)

I'm afraid so. I have difficulty with last week never mind eight years ago :) Anyway I just set up {{open-closed}} and {{closed-open}} - my first foray into creating templates! I guess I should stick something about it in a math help with formatting page if people like them else just the <nowiki> method. Dmcq (talk) 18:40, 14 March 2011 (UTC)
And I've tried them out on atan2. I've used {{math}} to format the contents rather than just {{nowrap}} as I think π looks better than π. Dmcq (talk) 22:10, 14 March 2011 (UTC)
A similar problem occurs when one tries to put a link to one of our articles into the comment part of an external link. See this edit to Monetary policy where Mattdarst tried to insert a link to Credit Channel into the comment field of an external link where the comment read ""THE STOCK OF CLOSED BANK DEPOSITS, DURATION OF CREDIT CHANNEL EFFECTS, AND THE PERSISTENCE OF THE U.S. GREAT DEPRESSION"". It caused the external link to terminate prematurely. JRSpriggs (talk) 01:27, 15 March 2011 (UTC)

I've seen bots "correct" semi-open intervals and similar mathematical notations. I'm aware of the nowiki solution, but seem to recall that this doesn't always discourage the more vigilant bots. A template solution seems best. Sławomir Biały (talk) 12:35, 15 March 2011 (UTC)

Which bots? Michael Hardy (talk) 18:04, 17 March 2011 (UTC)
Unfortunately, I no longer remember. I also don't know if this issue has since been fixed. It was a few years back that I noticed that some bots would sometimes parse mathematical markup incorrectly, and attempt to "correct" the problem. Sławomir Biały (talk) 18:33, 17 March 2011 (UTC)
I've set up {{open-open}} and {{closed-closed}} as well to complete the set. I hadn't thought about it before but they must be doing some special work to stop things like [1, 2] causing trouble. Anyway I use &#91; and &#93; instead in the templates. Dmcq (talk) 13:36, 15 March 2011 (UTC)
As an example {{open-closed|−π, π}} produces (−π, π] and the eventual code sent out to do this is <span class="texhtml" style="white-space: nowrap;">(−π, π]</span> Dmcq (talk) 14:07, 15 March 2011 (UTC)

I have formatted the argument (complex analysis) article using math type formatting for any inline mathematics throughout. I also set up a {{mvar}} template to do individual variables easily. Any comments gratefully received. Dmcq (talk) 15:14, 21 March 2011 (UTC)

Florentin Smarandache

The article Florentin Smarandache has been nominated for deletion for a 2nd time (AfD here); members of this project may be interested in commenting. Mlm42 (talk) 18:35, 17 March 2011 (UTC)

At least one editor there seems to be laboring under the impression that the subject of that article is a very influential mathematician. It is very frustrating arguing with this person. Sławomir Biały (talk) 01:31, 22 March 2011 (UTC)

Logarithm is up for FAC

Opine here. Jakob.scholbach (talk) 17:59, 21 March 2011 (UTC)

Probability notations

On the suggestion of one of the editors interested in the arbitration on Monty Hall problem, I started a little essay on mathematical notation in probability theory and its applications. First draft is at essay on probability notation; you can talk about it at: probability notation essay-talk. Comments are welcome! Especially if you can tell me that this is all superfluous because it's been done, and done better, before. Richard Gill (talk) 18:21, 21 March 2011 (UTC)

Duffin–Schaeffer conjecture

I've put an "orphan" tag on Duffin–Schaeffer conjecture, so get busy and think of a few (dozen) articles that should link to it. Michael Hardy (talk) 02:49, 22 March 2011 (UTC)

DYK: Criss-cross algorithm for linear optimization

A new article on the Criss-cross algorithm for linear optimization has been nominated for Did You Know?:

A (three-dimensional) cube

Corrections and comments are especially welcome. Best regards,  Kiefer.Wolfowitz  (Discussion) 03:48, 22 March 2011 (UTC)

Normal numbers page is broken

I was looking at Normal number and there seems to have been an edit by a well-meaning anonymous user which broke the markup. I would revert his edits, but I don't know enough about the subject to know if he was correcting an error in the article and made a mistake. Could someone with some more math skills than I take at look at the last two edits? Thanks.

DavidSol (talk) 01:34, 22 March 2011 (UTC)

I just noticed that Lindelof space was broken in much the same way for no apparent reason. It appeared to be caused by an edit adding a Korean interwiki, but now I wonder instead if it's a software problem. Sławomir Biały (talk) 01:43, 22 March 2011 (UTC)
Please note: Lindelöf space and Lindeloef are essentially identical spellings, whereas Lindelof is different (and incorrect). So if you can't type the umlaut, then write Lindeloef. Michael Hardy (talk) 02:51, 22 March 2011 (UTC)
At the time I was more concerned with having a link to the right place than valid typography, Michael. And yes, I can't type an umlaut at the moment. Sławomir Biały (talk) 10:46, 22 March 2011 (UTC)
I think it's just the wiki software getting confused. The anon at normal number undid his/her own change. The article got better after I tried purging it. I've seen similar issues with other unrelated pages today as well. —David Eppstein (talk) 01:45, 22 March 2011 (UTC)

Article should be in mathematics project?

Pick's theorem seems pretty applicable to your project. You might want to examine it and tag it if appropriate. Cliff (talk) 05:50, 22 March 2011 (UTC)

I added the project rating to the discussion page. Sławomir Biały (talk) 11:12, 22 March 2011 (UTC)
The article was already on List of mathematics articles, as well. That is the master list of articles in the project. — Carl (CBM · talk) 11:18, 22 March 2011 (UTC)

Arbcom decision on MHP: OR vs exposition in mathematics

The arbitration of the Monty Hall problem is nearing its decision phase.

Two proposals for the arbitration committee's decision concern Wikipedia policy on mathematical articles, especially original research versus secondary sources. Both proposals endorse editors' use of "arithmetic operations". This language could be of great concern to this project, and deserves your attention. Sincerely,  Kiefer.Wolfowitz  (Discussion) 23:47, 13 March 2011 (UTC)

Yes, it's of real importance to our project, and there are important nuances that neither version captures. But I thought we weren't supposed to edit Arb proposals?
CRGreathouse (t | c) 00:19, 14 March 2011 (UTC)
Editors may comment on proposals on the appropriate talk page. (I can strongly recommend against editing the arbcom pages that have warnings against civilian editing!)
I have asked two wise editors to watch the proceedings and this language, and I am sure that another wise editor already there can also comment effectively. (I commented informally on one arbcom member's talk page, and raised my concerns.) I believe that the most experienced editors should be trusted to advise ArbCom.  Kiefer.Wolfowitz  (Discussion) 00:44, 14 March 2011 (UTC)
Most worrying. Either version appears to make original research out of even routine examples. Sławomir Biały (talk) 01:19, 14 March 2011 (UTC)
Examples make or break articles, on WP and elsewhere. IMHO, we have to have the ability to make simple examples to interest readers, who would never be able to read research or even junior-senior math.
They should not issue any ruling on mathematics exposition. The social problems sufficed to make the MPH talk page a horror. If a mathematics article appears at ArbCom without social disorder on the talk page, then it may be reasonable for ArbCom to invent new principles to guide mathematics exposition. with apologies for being opinionated,  Kiefer.Wolfowitz  (Discussion) 01:33, 14 March 2011 (UTC)
I don't see how the proposed principles interfere with the presentation of routine examples, being routine they will undoubtably be able to be sourced. Paul August 02:01, 14 March 2011 (UTC)
Having looked closer at this I now have concerns about the proposed language. Paul August 12:55, 14 March 2011 (UTC)
Copying examples from reliable sources is generally not possible, due to copyright. While it is true that I've often seen people introduce errors into examples, there's not really a great alternative. Dcoetzee 02:27, 14 March 2011 (UTC)
Our examples are often similar to, but not identical with, those in other sources. The proposed mandate would in principle require that we copy sources step for step. Otherwise, it us generally not possible to find sources for each and every particular detail, even if the general principles are well-known. For instance, even simplifying a polynomial at the end of a longer example now requires sources in which the very same polynomial is simplified, which seems to be straightjacketing. Sławomir Biały (talk) 02:43, 14 March 2011 (UTC)

────────────────────────────────────────────────────────────────────────────────────────────────────I think that the OR rule together with the Copyright law make coverage of mathematics (or any other subject) impossible. You have to think (commit 'original research') to do mathematics. The only alternative is to blindly copy from 'reliable' sources which violates copyright. Of course, such copying and the verification that the source is indeed reliable also require thought (OR). So the rule against OR is an absurdity which should be repealed.
The reason we have a rule against OR is to try to avoid disputes about what is correct reasoning by appealing to an outside source. Notice that in mathematics, this is usually only necessary when one or more of the disputing parties is a crank or troll. However, refusing to allow an edit on grounds that it is OR is ultimately just an excuse for rejecting what we think is false without having to get the agreement of a crank or troll. JRSpriggs (talk) 03:05, 14 March 2011 (UTC)

This one is fairly complicated. I don't think it true that, outside of mathematics, OR and copyright makes coverage impossible. The problem is that an allowable rephrasing in most fields becomes OR in mathematics, as even a change in notation does not fall in the "routine arithmetic calculation" exemption in Principles 11. However, an expert mathematician's edits may qualify as allowable per se under WP:SPS, but may fail WP:COI. This might lead to weird results as using the diff adding the material as a reference, but it seems to satisfy the rules. I'll comment there if I can think of anything sensible to say. — Arthur Rubin (talk) 04:33, 14 March 2011 (UTC)
To be more precise, if I make an edit to an article on (say) the Axiom of Choice which I consider obvious, and it's reverted as OR, another editor can restore it sourcing it to the diff. — Arthur Rubin (talk) 04:42, 14 March 2011 (UTC)
After David Eppstein and Geometry Guy have alerted ArbCom of concerns about unintended consequences of the proposed wording(s), some ArbCom members have declared that they need some time to think about this issue.
I have followed only a couple of the ArbCom proceedings, but reading those few proceedings, I have impressed with the conscientiousness and intelligence of its members --- it is like a committee made up of Geometry Guys who actually read and think before writing!
Mathematicians should not cluck like a brood of chicken littles on the ArbCom pages. Let us leave our most experienced and articulate volunteers, whose work on WP is known to and respected by some ArbCom members, to discuss calmly the proposals with them. As the original chicken little,  Kiefer.Wolfowitz  (Discussion) 08:49, 14 March 2011 (UTC)
JRSpriggs's comment describes my experience. The WP community is able to control tendentious editing by agreeing that some edits represent OR (often OR by synthesis).
I am worried that the proposed language may influence featured-article and good-article criteria, rendering mathematical articles ineligible if they include examples for lay readers or explain concepts using consensus explanations that cannot be sourced: for the latter, see the example on my talk page, which could be challenged as OR by synthesis, I fear.  Kiefer.Wolfowitz  (Discussion) 09:12, 14 March 2011 (UTC)

Alternative wording suggested by Kiefer.Wolfowitz

I (K.W.) suggest the following changes:

  1. Change "arithmetic" to "mathematical".
  2. Add "providing context using standard mathematical results or providing elementary examples" to the list of accepted editing activities.
  3. Add the following: "Explanations, which use routine mathematical results or reasoning, are not considered "original research by synthesis", even if such routine mathematics are not referenced specifically for the application discussed: The mathematical results should be capable of routine referencing (easily referenced if challenged) and the article's editing should display an overwhelming agreement both that such derivations are routine (rather than original research) and that (to avoid simple OR proofs of important results) the result is unsurprising."

I would suggest that we strive for consensus language here, and then ask our leaders to communicate consensus suggestions to the ArbCom page.  Kiefer.Wolfowitz  (Discussion) 11:34, 14 March 2011 (UTC)

Elen asks for alternative wording

If you guys can get together a variant form of words quickly, and post it on the proposed decision talkpage, it can be put in as an alternative.

Providing examples is not a problem - slotting in different variables to a sourced method is not OR, nor is it really deriving from first principles. Glossing should not be a problem if you have some referencing to show the general applicability of the gloss. I do have concerns with the example Kiefer gave on his talkpage [32], but I'd have more problems with the old version that the new, assuming that somewhere in the sources cited are the two equations, the definition of limits, and the information about strictness in relation to Minkowski sum. It is the old example which seems to have lots of derivations without referencing. --Elen of the Roads (talk) 14:20, 14 March 2011 (UTC)

I refactored and emboldened Elen's request for help, which is most important!  Kiefer.Wolfowitz  (Discussion) 15:12, 14 March 2011 (UTC)
@Elen, I updated the references in the example. For sequential convergence, the most elementary exposition is John Fridy's Analysis:The Theory of Calculus, and I am sure that the results are available in the Green & Heller reference (and probably Arrow & Hahn, Mas-Colell, etc.: I am away from my references this week). Certainly the strictness of the Minkowski sum is covered by Rockafellar (pages given) and also Schneider: I believe that Rockafellar has a sequential discussion of limits, also. The equation (inclusion) appears in Ekeland (pages given).  Kiefer.Wolfowitz  (Discussion) 14:42, 14 March 2011 (UTC)
I made this proposal. It would be best for others to strive for a consensus statement, following Elen's very kind and thoughtful statement of interest.  Kiefer.Wolfowitz  (Discussion) 14:46, 14 March 2011 (UTC)

I've only had a chance to skim most of the Arbcom case, but it seems like the main issue is the detailed derivations from first principles. The language used should more closely reflect the actual problem, rather than casting an overly broad net against anything that could possibly be construed as original research.Sławomir Biały (talk) 16:10, 14 March 2011 (UTC)

I have posted an alternative wording on the workshop page. Geometry guy 22:10, 14 March 2011 (UTC)

Teaching and OR

I don't have much to say about the MHP apart from thanking the people who have commented on the arbcom page. I did want to say something related. Lately, after discussion at WT:TECHNICAL and WT:NOR, and looking at WP:NOT, I have been thinking about the underlying issues that lead to these disagreements. I'm only thinking about articles at the advanced undergrad level and beyond here; articles on basic topics are less problematic because there are plenty of low-level references. But there are few references on advanced topics that are accessible to an untrained reader.

Three points:

  • There's a tension between making "reference" articles that are primarily useful for people who already know the topic, and making "didactic" articles that help people who don't know the topic learn it. When WP:NOR is interpreted more strictly, that leads us to favor specialists over learners. WP:TECHNICAL, on the other hand, asks us to lean more towards learners, by explaining things in our own words, using analogies, and giving examples. These two policies are naturally opposed to each other.
  • WP:NOT has the same opposition inside it, saying both that articles should not be written for specialists and that articles should not be written to teach people about the topic at hand. For example, it says both "A Wikipedia article should not be presented on the assumption that the reader is well versed in the topic's field." and "The purpose of Wikipedia is to present facts, not to teach subject matter.".
  • These disagreements go back all the way to the founding of Wikipedia. There was never a time when all the articles "followed policy" after which time the articles began to "violate policy". Instead, the articles have always been in a state of flux, and the policies have never perfectly captured the balance between the goal to be a reference work and the goal to present material to students who are learning it for the first time.

I think that we do a reasonable job at balancing these things in our articles, both overall and in mathematics. My main point is that if we realize that Wikipedia's goals are sometimes in conflict with each other, it can help us find a middle ground. — Carl (CBM · talk) 13:43, 14 March 2011 (UTC)

Let's not forget IAR

Seems to me we are in danger of becoming too rule-obsessed, hierarchical and obsequious over this. If Arbcom produces a ruling which appears to prohibit simple explanatory examples in mathematics articles, then common sense tells us this cannot be what was intended - either Arbcom have mis-worded their statement or we have mis-interpreted it. As explanatory examples obviously improve the encyclopedia, IAR tells us we can use them anyway. At the same time, we can either ask Arbcom to clarify their ruling, or simply drop them a hint by awarding them a trout. Gandalf61 (talk) 15:50, 14 March 2011 (UTC)
This ruling, percolating through WP like phosphorous from a lava chamber (! ;) !), may make it impossible to get articles approved for feature article status, although it probably would have no effect on most articles.  Kiefer.Wolfowitz  (Discussion) 16:00, 14 March 2011 (UTC)
Personally, I don't think it's worth focusing on featured article status anyway. The goals of the FA wikiproject are not necessarily aligned with our goals, but that's OK. Wikipedia can accomodate both. — Carl (CBM · talk) 16:31, 14 March 2011 (UTC)

New wording

In response to comments made by editors from this WikiProject, Arbitrator Elen of the Roads has proposed an alternative wording of the principle, which caused concern here, for other arbitrators to consider and vote upon. You can comment on the proposed principles at Wikipedia_talk:Arbitration/Requests/Case/Monty_Hall_problem/Proposed_decision. Geometry guy 23:42, 14 March 2011 (UTC)

Thanks again for working with this. — Carl (CBM · talk)

The links being said to show Original Research

Regardless of the OR statement of principle that ArbCom may or may not adopt, I am concerned by what the examples of what they are claiming is OR in their statement of facts -- specifically the three claimed examples cited at Wikipedia:Arbitration/Requests/Case/Monty_Hall_problem/Proposed_decision#Article_has_been_subject_of_original_research Article has been subject of original research.

As far as I can see (more detail on the decision talk page here, here, and here), none of these three examples properly constitute original research.

It seems to me that this is no small issue, because the examples Arbcom cite are going to be the most direct operational indication of what they consider to be OR, and how they mean whatever principles they adopt to be interpreted.

I'd welcome second and further opinions on these examples, and whether we think they are OR or not, because the Arbcom members are refusing to engage on the merits of these links; yet are still happily voting for the proposition. Jheald (talk) 09:55, 15 March 2011 (UTC)

This is extremely concerning for me as well. There are thousands of words on that talk page detailing how horrible these words are, and no one except Elen (which is epically wrong bout what is OR and what isn't) seems to bother reading these concerns. Perhaps we should write message on the arbitrator's talk page to address the concerns raised on the talk page about how the all the proposed wordings are utterly horrible. Headbomb {talk / contribs / physics / books} 21:53, 16 March 2011 (UTC)

WP:CALC seems open to improvement

Even some ArbCom members refused to vote on using its exact current wording in their principles (which they are still struggling to formulate in that respect). So, clearly WP:CALC is deficient. I suggest you guys take this opportunity to improve the wording in the policy, so you won't have to put out this kind of fire in the future. All the best, Tijfo098 (talk) 18:27, 16 March 2011 (UTC)

I don't think wp:calc was ever meant to be used as a guideline for quantitative disciplines, rather the sort of routine calculations that one does in history and biography articles for instance. It's obviously insufficient to cover more mathematical articles, but I don't know if it's worth emending the policy, or just clarifying its intended scope: it doesn't exclude things that aren't just pure arithmetic from the more quantitative articles, provided no original research is committed. Sławomir Biały (talk) 19:00, 16 March 2011 (UTC)
Clarifying its scope would be my choice too. We don't want editors to start making inferences in other article claiming that "A implies B" from RS1 "B implies C" from RS2 therefore ... because in social science in particular B from RS1 is often not quite the same as B from RS2. Yes, math and a few closely related formal sciences are an epistemic exception, where inferences like the above are possible without much "OR". But I'm not sure how to say that without being too pretentious or too insulting. The current arbcom wording, something along the lines of: it's fine if it has consensus and nobody asks for citation, seems better, and has the elephant standing for it. -) Tijfo098 (talk) 23:29, 16 March 2011 (UTC)

Latest proposal

There is a new proposed wording. It works for me. Does anyone else have any thoughts about it? Sławomir Biały (talk) 14:11, 17 March 2011 (UTC)

It leaves matrix calculus as a dead article, but that may be for the best. The only sourced notation so far provided is misleading, and (IMHO) unusable for real mathematics. — Arthur Rubin (talk) 15:00, 17 March 2011 (UTC)
The essential thing I think that WP:CALC is missing is a reiteration that the methods must not be novel and it must not support a novel conclusion. Basically it shouldn't support original research. An example illustrating a method or a straightforward indication of how a result is obtained is okay. Saying "it is okay because I have only used standard methods to derive it, it is straightforward mathematics" is an immediate red flag. Dmcq (talk) 15:10, 17 March 2011 (UTC)
I see WP:CALC as a separate entity from original research in mathematics. That's meant to cover routine "everyday" calculations (like in a biography or history article), rather than derivations in quantitative articles. I think the Arbitration Committee has, with this last proposal, finally realized that WP:CALC is ill-suited as a criteria for original research in mathematics. There seems to be some support here for clarifying the intended scope of WP:CALC. Sławomir Biały (talk) 15:17, 17 March 2011 (UTC)


The decision has been publicized.  Kiefer.Wolfowitz  (Discussion) 00:44, 25 March 2011 (UTC)

MathJax update

Just to let you know, I have updated my mathJax user script to recent version 1.1 of MathJax. Notable change is the support for webfonts via CDN (i.e., no local font installation requirements). Details at the user script documentation page. Feedback welcome. Nageh (talk) 21:37, 23 March 2011 (UTC)

Currently on the Main Page ...

... is John Milnor, who has been awarded the Abel Prize. The article is OK as such, but could obviously be expanded quite a bit. Charles Matthews (talk) 09:43, 25 March 2011 (UTC)

Drinker's paradox

There seems to be a bit of hostility to the newly-listed article Drinker's paradox on the article's discussion page. Various editors are grumbling about deletion, original research, etc. I thought perhaps someone in the project should investigate. Sławomir Biały (talk) 12:16, 25 March 2011 (UTC)

You mean Drinker paradox, right? Most of the opposition seems to be about the title; it is argued that it is not a "paradox". Which, as far as it goes, I would agree with, but it can still be an interesting and possibly notable illustration of some tension between the mathematical tradition of using English to express logical formulae, and what English sentences usually mean in an everyday setting. –Henning Makholm (talk) 12:31, 25 March 2011 (UTC)
This sort of thing is covered by WP:COMMONNAME. This is clearly the common name as it is found in a number of books, which by the way also means it will not be deleted. Whether it is actually a paradox or not is only slightly relevant and certainly would not trump the common name criterion in this case. Lots of people have this funny idea that a title is the article whereas it is simply a way to find the article which is what common name is all about. Dmcq (talk) 13:00, 25 March 2011 (UTC)
Could you add references to some of that number of books to the article? I found it strange that the only source it gives is to Smullyan's book, which according to the article itself called it the "drinking principle" rather than the "drinker paradox". So the title is currently unsourced, which is not good when it has been seen to cause contention. –Henning Makholm (talk) 13:31, 25 March 2011 (UTC)

maybe make a redirect from "drinker principle" too? regards "difference between [propositional logic] and what English sentences usually mean": no. there is no difference there. the grammar, syntax,, AND semantics is exactly the same; it is a perfectly ordinary sentence and the meaning of it is no different whether you address it with formal logic or with "ordinary interpretation". the difference lies in what happens after the sentence has been linguistically parsed and what not converted into formal relations. up to that point nothing has diverged, and at that point you will have the same thing in either case. once in the form of formal relations, however, differences of two types are introduced: 1.) implicit assumptions, and 2.) rules of logical manipulation. regarding 2.), a person untrained in logic is more likely to use the rules given to them by instinct, which are incorrect. well, in a certain sense. they are not designed to be correct, they are designed to be quick, and to be decent approximations, and to the end they serve well. but, fundamentally, there are incorrect. regarding 1.) the sentence as is gives incomplete information, from a logical point of view, eve. do you mean just right now? this round? ever? here logic differs from conventional usage, in filling in this missing information: logic always refers to the instant, unless otherwise explicitly noted. whereas conventionally we fill in this missing information with "...ever...". and this is how one gets to the difference in conclusions. they are both actually correct, it is simply a matter of how you fill in the missing information. Kevin Baastalk 13:40, 25 March 2011 (UTC)
I suppose in that sense it is a "paradox", because most (if not all) so-called "paradoxes" really just appear as such because there was a missing piece of information that we didn't realize was missing. really when you include the missing information you see that there is no paradox at all. nature simply does not do "paradoxes". Kevin Baastalk 13:43, 25 March 2011 (UTC)
I just tried out "Drinker paradox" | "Drinker principle" in Google books and scholar and there's two pages of references, some to principle, some to paradox and various ones having a 's after the first word! At least there's paradox ones predating the article, I keep worrying that somebody will stick a wrong title in and that takes over from what people were actually using :) Dmcq (talk) 14:14, 25 March 2011 (UTC)
A paradox is an *apparent* nonsensical or *apparently* false statement, which on careful consideration can be seen to be correct after all. So it seems to me that the drinker paradox is a paradox indeed! Or: it shows that ordinary logic is maybe not so appropriate to logical reasoning in everyday life, as most of us thought. Quite a few paradoxes in mathematics can be seen as symptomatic of inadequacies of the "usual axioms* of present day mathematics. But either way, this is the sort of thing that is usually called a paradox, so I see no problem at all with the nomenclature. Richard Gill (talk) 16:07, 25 March 2011 (UTC)
The term paradox is fairly informal. Any puzzling statement may be called a paradox. Paradoxes are not a big deal, because they can be resolved. A paradox that is a big deal, and that cannot be resolved (easily) is called an antinomy. In order to resolve an antinomy, one has to forsake an important part of one's intellectual heritage. The Barber paradox is resolved by accepting that, well, there just isn't such a village with such a barber. In order to resolve an antinomy, one may have to reject long standing accepted fundamental principles. Over the course of history antinomies eventually become mere paradoxes because our knowledge and language catches up with them.Greg Bard (talk) 16:37, 25 March 2011 (UTC)

Tai's method

Apparently someone rediscovered the trapezoidal rule and managed to get it published. See Tai's method. Just an article about the trapezoidal rule under another name? Or an article about how something weird like that can happen? Either way, is the article in some way worth keeping? Michael Hardy (talk) 03:49, 26 March 2011 (UTC)

It is claimed that more than 100 works cite the article. Michael Hardy (talk) 03:53, 26 March 2011 (UTC)
If the claimed citations do check out, I'd say it is ok to keep it. Also imho this is partially not a math issue, but a question for the applied field/domain in which the "discovery" was made (here biology, medicine I guess). Many apllied sciences have there own names and versions of math theorems and though I can't think of another example on top of my head, I'm pretty sure there is quite a number of such cases. If the name/method in question is well known/established enough (not among the math community but in the domain in which it originated), WP should provide an article or a redirect. Which of the 2 options is better needs to be judged on a case by case basis.--Kmhkmh (talk) 13:21, 26 March 2011 (UTC)

Use of maths symbols in html

The 'Math and logic' symbols in the editor include a load of special symbols. Is it okay to use all these in maths articles? For instance can I say rather than in inline maths? And by the way I don't believe I should bold that as in , would that be right too? Dmcq (talk) 12:56, 26 March 2011 (UTC)

The WP:MOSMATH, which can always be revisited, recommends the ordinary boldface R to the blackboard bold ℝ, due to the latter being potentially unsupported in some browser configurations. I agree that is wrong (in fact, I don't think this can be typeset in LaTeX easily either). I really don't like the way inline PNG looks in the middle of running text, so I would avoid using the <math> form in any case. Sławomir Biały (talk) 13:41, 26 March 2011 (UTC)
Well I guess I better raise something at MOSMATH then because it seems silly to have them prompted in the editor and then deprecate them. I think I'd prefer to have the text and the stand along formulae match up better and having those symbols available would help greatly with that but it really needs to be checked. Dmcq (talk) 15:49, 26 March 2011 (UTC)

"Inline" as opposed to "displayed" use of TeX within Wikipedia has always been problematic. Things like the following can happen:

blah blah blah blah blah blah.

Obviously the e should be at the same level as the surrounding text and the x3 should be in superscript, but that's not what happens. Also on some browsers, the part in math tags looks comically gigantic. You can also get siuations like this:

There are examples (such as
) in which etc. etc. etc.

The right parenthesis is on the next line! It also happens with periods, commas, etc. "Displayed" TeX, on the other hand, generally looks quite good:

So I generally prefer non-TeX notation in an "inline" setting. Michael Hardy (talk) 00:54, 27 March 2011 (UTC)

N-dimensional space

Over at Talk:N-dimensional space we're having a traditional merging discussion. The issue is that these articles (and probably others) all contain redundant material: Space (mathematics), Vector space, Dimension, Dimension (vector space), Basis (linear algebra), Euclidean space, Manifold (mathematics), N-dimensional space. So I thought I'd bring it up here.

My opinion: Each kind of space (vector, Euclidean, manifold, etc.) obviously deserves its own article. Additionally the Space (mathematics) and Dimension articles seem useful as catalogues/overviews. But Dimension (vector space) could be merged into Basis (linear algebra) and/or Vector space, and N-dimensional space could be merged into Space (mathematics) and/or Dimension.

Any comments? Mgnbar (talk) 16:39, 26 March 2011 (UTC)

Special case

Special case is currently a stub article that could use a lot of work, both within the article and in other articles that should link to it. Get busy. Michael Hardy (talk) 00:45, 27 March 2011 (UTC)

QUERY - Aren't changes on a page supposed to be reported????????????????

Hi! I use Wikipedia very often and thought for sure that a policy of yours was to add in a "page history" page that showed any changes to an article and by whom for that page?

I ask because your page on Summation had early in its write-up an image of an example of Induction ( ) ... odd that that very image wasn't there just a few days ago for another image that was the exact same equation but in different form.

I looked for the history of why and who changed that image because its odd I been coincidently writing a paper on the example of Induction used of the original image and linking this very page for that image and sending that paper to leading Set Theory specialists and other university piers and that image was very helpfull in dealing with the issues the paper regarded. Now suddenly someone changed the image to a different example of Induction and I find the timing very peculiar. It doesn't change anything about my paper except for it to be easier to understand for anyone needing to see the example of Induction I was using from here but is now changed. I only linked to the page on Summation.

Anyways, how did that image change on the Summation page without anyone ever knowing it happened or why in the pages history?? — Preceding unsigned comment added by G2thef (talkcontribs)

The history of summation is here. The sum you mention was put into the article on April 17, 2010, in exactly the same form it is there now. It is possible that some time in between then and now, someone changed it into the form you prefer and that is was then soon after changed back, but that sort of thing is much harder to find since it would take scanning all the changes to the article rather than simply doing a binary search. —David Eppstein (talk) 20:50, 27 March 2011 (UTC)

The assistance of WikiProject Mathematics requested

In looking over some project work I did for an undergrduate computing degree I noted that the academic supervising me had come up with what he called a 'slew' transform.

I've put a rough note in my userspace at Wikiversity (because of concerns about verifability here) The link is :

I'd appreciate someone from the WikiProject that understand 3D transformation stuff, to help provide a better citation , or indeed a creative commons licensed proof that will show what's stated is correct.

A 'slew' transform is a transform where 'distances' parrallel to an axes before a 'slew' are preserved, as opposed to a 'shear' where they are not.

I'm also trying to understand how to abstractly define a 'grid'. ( The best definition I can think of for 2D is that a 'grid' is a regular arrangement of points and lines that fills a plane.

For a 'cubic' style of grid, this regular arrangement can be more formally considered as a (Lattice Graph?) formed by the Cartesian product of 2 path graphs, representing lines perpendicular to each other. However, I'm thinking I need to put in some kind of constraint on where the grid points can be placed, and I'm not entirly sure how I specfiy that constraint in an abstract math way...

A 'polar' style of grid is however more complex, being the Cartesian product of a number of path graphs(?) with some kind of cycle graph , ( aka a Prism Graph?). Again some kind of constraint would need to be defined on where grid points can be placed..

And finally Has this sort of thing been done before in a textbook a math noob can understand? Sfan00 IMG (talk) 22:36, 27 March 2011 (UTC)

Regarding your first request, I am not clear exactly what the text on that page is trying to say, but I do not see how the examples can be correct, as they claim to modify the Z or Y axes but do nothing in those directions.
Regarding your second request, I think you want lattice (group).
Also, I suggest you ask these types of questions at Wikipedia:Reference desk/Mathematics in the future. Ozob (talk) 23:23, 27 March 2011 (UTC)
Thanks, re the 'slew' transform, can you leave some thoughts on my Wikiversity talk page ?

The context of the slew transform by the way in the original project was based on being able to convert a 'cubic' lattice to be transformed into a 'heaxagonal' or 'parallelogrammic lattice' one (in 2 dimensions).

Can you suggest a better way to describe what a slew transform appears to be doing, because I'd like to be able to explain it clearly to other people? Sfan00 IMG (talk) 09:52, 28 March 2011 (UTC)

You might find the explanation at Affine transformation#Affine transformation of the plane more helpful. The problem you mention is a special case of what is talked about there. Charles Matthews (talk) 10:17, 28 March 2011 (UTC)

Minimal negation operator

While this unreferenced article looks cool, I can't find anything in google books to support it. WP:OR? Tijfo098 (talk) 05:21, 25 March 2011 (UTC)

The talk page there seem to indicated I'm right (the creator is now indef blocked for something similar.) Tijfo098 (talk) 05:23, 25 March 2011 (UTC)
Looks pretty original to me. — Arthur Rubin (talk) 06:32, 25 March 2011 (UTC)
Wow. A Jon Awbrey article lavishly illustrated by Lipedia. Unfortunately it appears that Peirce never wrote about anything else with a similar name. In that case we might have hit a logic crankery jackpot. Let's take this to AfD. If this was a real notable topic, some mathematician would have noticed through all the years and especially since 11 August. Hans Adler 06:59, 25 March 2011 (UTC)
I just had a look through Awbrey's contributions and the following just strike me as being iffy. Some are redirects, others are just bits of Pierce's writings that probably could be a paragraph somewhere else I think. Things like boolean domain I just cant see the point of a separate article from boolean but logical matrix I can see is probably okay. Others like sign relation I just plain don't understand. Semeiotic seems to be some variant spelling of Semiotic by Charles Saunders Pierce.

I guess most of these are perfectly okay but is there some that even someone familiar with Charles Saunders Pierce isn't familiar with or thinks is unnecessary? Dmcq (talk) 18:50, 25 March 2011 (UTC)

I recognize most of these terms as being used by Peirce in his logical writings. Peirce's preferred spelling "semiotic" as "semeiotic", as you suspected.
I have only an amateur understanding of his logic. Peirce had an anti-Fisherian approach to terminology, where he thought it bad sport to use an existing word for a new idea (and would have denounced the Fisherian vice of switching between the two, e.g. "information", etc.). This explains why Peirce introduced so much novel terminology, and why he was less successful as a salesman than Fisher.  Kiefer.Wolfowitz  (Discussion) 20:47, 26 March 2011 (UTC)

Logical graph is a nebulous article that could use work. I think the term existential graph has been used more recently, and perhaps even by Pierce. Tijfo098 (talk) 04:09, 30 March 2011 (UTC)

Jacob Barnett

There is a deletion discussion under the auspices of our project that could benefit from its input. Sławomir Biały (talk) 00:21, 31 March 2011 (UTC)

Apr 2011

Montante's method

Is this a notable article? Jakob.scholbach (talk) 21:19, 27 March 2011 (UTC)

It's entirely unreferenced, and there are no google scholar hits. I am suspicious of the supposed origin of this algorithm as well: the attribution feels like self-promotion and original research. At any rate, there is a well-known fraction-free algorithm called the Bareiss algorithm from 1968 that predates the date of 1973 given here. As far as I can tell, the two algorithms are the same or very nearly the same. Sławomir Biały (talk) 21:34, 27 March 2011 (UTC)
Eswiki has an article about the supposed discoverer. Doesn't look quite like run-of-the-mill self-promotion (modulo my lack of knowledge of Spanish). Could possibly be a case of people naming the result after the one among several independent discoverers that they identify with the most. If it's really the same thing, it ought to redirect to a common article, which then should document the various names. –Henning Makholm (talk) 22:08, 27 March 2011 (UTC)
But there is no evidence of anyone calling it Montante's method, and I can't find any reference to Montante regarding the method. The interview here refers to apparently unpublished papers by Montante Pardo, in which he apparently calls it the "Método Montante". That's more than a little questionable, and does look very much like self-promotion and original research to me. Sławomir Biały (talk) 22:21, 27 March 2011 (UTC)
There are some Google hits in Spanish that look like the algorithm is taught under that name at various institutions in (mostly) Mexico: [33] [34] [35] [36]. These links appear to be too different to all be self-promotion.
It feels at least plausible that some Spanish-speaking project member would be able to dig up a reliable source for the name. Anyone have access to a collection of Mexican linear algebra textbooks? –Henning Makholm (talk) 22:52, 27 March 2011 (UTC)
Perhaps Google scholar and Google books don't index Spanish-language books, but there is an utter absence of any kind of relevant hits for "Metodo Montante" or "Montante's method", and variants in reliable published sources. This very algorithm appeared in a widely cited article by Bareiss five years before Montante allegedly came up with it. It seems to be a neologism that should be avoided. Sławomir Biały (talk) 23:09, 27 March 2011 (UTC)
So, should it be merged into the article on the Bareiss algorithm and attributed to him? JRSpriggs (talk) 09:30, 28 March 2011 (UTC)
Since the article seems to be of rather low quality, I nominated it for deletion. Jakob.scholbach (talk) 19:46, 31 March 2011 (UTC)
People here seem to call it Montante's Method. I found an interview published by a different university in the same city, here. I cannot truly attest to whether this method was found independently or not, but it is a method whose credit is given to him, at least here in the city. Perhaps another Mexican could confirm if the term is used outside of Monterrey/Nuevo León? And about the article deletion, please understand that EsWiki is waaaay behind EnWiki. If we were to quality-test every article, most would most likely disappear. While I agree that articles in Spanish should also follow Wikipedia's guidelines, I must also say that EsWiki is still a work in progress, and deletion of articles will damage more than what it would help, unless information found on them is proven to be actually false. Also, don't always expect Google Scholar hits about Mexican universities, you fail to see the (possibly sad) context they work in.— Preceding unsigned comment added by (talkcontribs) 02:00:48, 14 October 2013 Note:Comment added after archival.···Vanischenu (mc/talk) 00:51, 30 October 2013 (UTC)

Fourth Dimension

An editor is insisting in marking the lead of Fourth dimension as dubious in "In mathematics, the fourth dimension, or a four-dimensional ("4D") space,[dubious – discuss] is an abstract concept derived by generalizing the rules of three-dimensional space". They say a four dimensional space could be any sort of space not necessarily Euclidean whereas others have said it referes in this instance to an extension of Euclidean 3-space. I would like to remove the dubious tag or otherwise resolve this. This is a bit similar I guess to the N-dimensional space business mentioned in a section above but as far as I can see there has been no real follow up to that, also I think they are a bit different in that N-dimensional space is actually used for many other things like configuration spaces whereas four-dimensional space is rather specific. Talk is at Talk:Fourth dimension#Title?. Dmcq (talk) 11:00, 31 March 2011 (UTC)

A mathematician could use the term 4-dimensional space in any discussion of a "space" that has "dimension" 4. For example, a vector space (over any field) with a basis consisting of 4 elements, a manifold whose charts map to R4, a manifold whose charts map to C4, a topological space of Hausdorff dimension 4, etc. So I feel strongly that 4-dimesional space should not be restricted to 4-dimensional Euclidean space. Mgnbar (talk) 12:57, 31 March 2011 (UTC)
The definite article seems out of place in that article's lede. CRGreathouse (t | c) 13:12, 31 March 2011 (UTC)
My understanding is that it's a historical usage, and the name of the article was taken from the book The Fourth Dimension by Charles Hinton (1912). — Carl (CBM · talk) 13:14, 31 March 2011 (UTC)
@Mngbar: If you ask a mathematician about "a point in 4-dimensional space", with no qualifiers and not saying "a four dimensional space", she will immediately assume you mean 4D Euclidean space. The term "4-dimensional space" as a proper noun is completely tied to Euclidean spaces in ordinary mathematical usage. We have to add other words to make it clear when we mean some other sort of four-dimensional space. — Carl (CBM · talk) 13:14, 31 March 2011 (UTC)
You raise a good point. Out of context, it would be unlikely for the mathematician to be referring to a particular complex manifold or topological space. However, I argue that "a point in 4-dimensional space" would just as commonly refer to an element of a four-dimensional vector space. In teaching, we often draw pictures of vector spaces, even when we have not assumed any Euclidean structure on them. Furthermore, a major point of contention at Talk:Fourth dimension is whether "four-dimensional space" should default to Euclidean or Minkowski space. There is a strong physics influence here, and maybe there should be. Mgnbar (talk) 13:43, 31 March 2011 (UTC)
Looking at the lead again the 'a' in 'a four dimensional space' looks out of place to me but the 'the' in 'the fourth dimension' is correct in the context of referring to 4 dimensional Euclidean space. The lead does talk about that physics deals with four dimensional spacetime but doesn't say strongly enough that the article is just dealing with a mathematical space rather than spacetime. The fourth dimension is also referred to in things like 'The Time Machine' where they mean something like a four dimensional Euclidean space where we are confined to a layer like in Abbot's book Flatland rather than anything like the modern conception of spacetime. Dmcq (talk) 20:44, 31 March 2011 (UTC)
There may be a strong 'physics' influence here, but in a broad way. In my experience, physicist avoid the term fourth dimention in favor of space-time. Ocassionally the will use the term 3+1 dimensions. On the other hand, there seems to be a popular understanding that time is the 'fourth dimension' such as what Dmcq mentions above. Without proof, I would guess that the most common reason for a user to goto the fourth dimension article is because of this popular misunderstanding of space-time. Some fraction would be interested in 4 spatial dimensions as well looking for concepts related to a non-self-intersecting Klein bottle, etc. I can't speak at all about why mathematicians would use it.
I have ran into similar arguments in other articles where people insist that space-time is four-dimensional or 4D (instead of 3D+1 or better yet not mentioning dimensions at all). I think part of the problem is combining fourth dimension with 4 dimensional (4D) space. To me at least 'fourth dimension' is a colloquial expression that could mean the extra dimension of either space or time, while 4 dimensional space could mean any group of 4 parameters and 4D is definitely 4 spatial dimensions.TStein (talk) 00:04, 2 April 2011 (UTC)

Gauss–Codazzi equations vs. Gauss–Codazzi equations (relativity)

I have no idea what these two are about exactly, but these two articles seems to be about the same thing. Opinions on what should be done? Headbomb {talk / contribs / physics / books} 19:16, 31 March 2011 (UTC)

They're the same, but both articles suffer from irreconcilable notational incompatibility. Sławomir Biały (talk) 21:35, 31 March 2011 (UTC)
Well I redirected Gauss–Codazzi equations (relativity) to Gauss–Codazzi equations. If someone wants to bother doing a merge, go right ahead. Headbomb {talk / contribs / physics / books} 19:21, 1 April 2011 (UTC)

Making sense of 0.000...01

Our page lists a number of frequently asked questions about 0.999... One of the answers to these questions deals with the "number" 0.000...01 (with an implied infinity of zeros before the last digit). The answer asserts, correctly, that this number is meaningless as a real decimal. I added a brief parenthetical comment here to the effect that one can make sense of such a number in a proper extension of R, providing a link to a page where this is discussed. The parenthetical remark was apparently too much for the guardians of purity at 0.999... and was reverted, most recently here. I would appreciate some input. Tkuvho (talk) 20:24, 31 March 2011 (UTC)

I think that is likely to just confuse people more. I don't have anything against the hyperreals, but I think that when people are already confused about something that's part of the grade school curriculum (real decimal expansions), we should be particularly hesitant to point them at even more difficult things that are not even part of the usual undergraduate curriculum (hyperreal decimal expansions). So I think the point of the FAQ is to be very simplistic. The article itself does discuss infinitesimals, as I think it should. — Carl (CBM · talk) 20:30, 31 March 2011 (UTC)
Are infinite decimals part of the grade school curriculum?? You are lucky if you get them in high school in many cases. The purpose of a FAQ page is not to address a particularly young segment of our readership, but to attempt to answer typical questions that might arise on the talk page. A number of inexperienced editors have reacted with interest to the suggestion that infinitesimals have a role to play here. Frankly, I don't see why the talk page is any less of a legitimate place to discuss infinitesimals than the 0.999... page itself. Tkuvho (talk) 21:00, 31 March 2011 (UTC)
I have seen grade school curricula with the fact that 0.999... = 1 (specifically, the 10x - x = 9x proof). Ozob (talk) 21:28, 31 March 2011 (UTC)
You mean, "the 10x - x = 9 proof". --Boris Tsirelson (talk) 07:01, 1 April 2011 (UTC)
Yes, thank you. Ozob (talk) 11:29, 1 April 2011 (UTC)
The fact that only rational numbers have repeating decimal expansion, and the algorithm for finding the corresponding rational from such an expansion, are common topics. Here is an NCTM worksheet that puts that skill in middle school. [37]. — Carl (CBM · talk) 21:47, 31 March 2011 (UTC)
Those are extremely useful formulas, indeed. From the point of view of a wider continuum, they hold up to an infinitesimal error if the infinity of periods is interpreted in terms of an infinite hypernatural. From the real view point, all such infinitesimal differences are erased by an application of limit or standard part. None of this contradicts the fact that student intuitions about "0.000...1" have a fruitful mathematical implementation. Tkuvho (talk) 04:56, 1 April 2011 (UTC)
I think the game Hackenbush is a good illustration that these ideas are not altogether theoretical, that there may be very good reasons for saying that one 'value' is larger than another even though sticking them on the real line leaves no room for difference . Dmcq (talk) 11:45, 1 April 2011 (UTC)
Excellent point. There are several ways of making sense of the "0.000...01" intuition, Hackenbush being one of them. These are closely related to the surreals. Meanwhile, the maximal surreals have recently been shown to be isomorphic to the maximal hyperreals. So really it's the same basic idea. But getting this past the purists at the FAQ page seems to require a titanic effort. They are currently busy eliminating any vestiges of an alternative to the reigning dogma. Tkuvho (talk) 12:18, 1 April 2011 (UTC)
The article itself already does cover infinitesimals, of course; I don't think anyone is removing that. It seems to me that an FAQ does not need to cover every alternative theory. The point of the FAQ is to give very simple answers to a few questions, not to replace the main article. — Carl (CBM · talk) 12:22, 1 April 2011 (UTC)
Here's an analogy. Suppose we had a FAQ in solar system about whether the sun orbits a stationary Earth or the Earth orbits a stationary Sun. The right answer to that would be "modern science accepts the theory that the planets of the solar system are in orbit around the Sun (heliocentrism)." We would not want to go into length about how a few modern scientists have been interested in geocentrism and about how it is possible, after some effort, to reformulate things in a geocentric coordinate system. The lack of infinitesimals on the real line is similar: the thing which students need to learn first is that there are no infinitesimals on the real line. Only after they are comfortable with that fact could they be in a position to study other systems in which there are infinitesimals, but which (like geocentrism) are considered only potentially-useful fictions by modern researchers. — Carl (CBM · talk) 12:31, 1 April 2011 (UTC)
Thanks for your comment. I am obviously not going to pursue the FAQ thread if you are against it. Perhaps we can settle for a more meaningful mention of infinitesimals in the lede of 0.999.... The following comment is somewhat predictable, but I will make it anyway: I agree with your geocentric/heliocentric analogy, provided the roles are reversed. Tkuvho (talk) 14:05, 1 April 2011 (UTC)
Yes, the article should definitely discuss infinitesimals in some depth, since infinitesimals are the heart of the issue from my perspective. Another analogy that I have in mind is quantum mechanics. Bell's theorem shows that quantum mechanics is incompatible with the naive idea that an event in one place must take some amount of time to influence events in another place. Surely many people would find that surprising at first, and there are always some people who look for a way to work around the theorem (so-called "loopholes"). But the overall consensus of physicists (as far as I have been told) is that the theorem is correct in rejecting local variable theories in quantum mechanics. For an outsider like me, the primary question to ask is "why do physicists feel that way", rather than "what arguments can I use to avoid accepting what the experts have accepted". Similarly, I think that an article on 0.999 should emphasize why mathematicians treat it as equal to 1, which not only tells readers that fact but helps demonstrate the methodology of mathematics. — Carl (CBM · talk) 14:54, 1 April 2011 (UTC)

The readability of articles

I have just been reading a mathematics article about the Halting Problem (Turing et al) and found it to be very difficult to read. A lot of text books on subjects particularly in the field of science and maths have been written in this style and it leaves the reader frustrated and confused. Surely an encyclopedic article should be accessible to the widest audience possible? I think some simplification of the language with perhaps more steps and examples would help to get across to the reader some of the concepts involved. Readers are generally not stupid people (else why would they be there) but the knowledge should be communicated better. Language, next to knowledge, is the most important asset an encyclopedia can have.

Sam- Helsinki, Finland —Preceding unsigned comment added by (talk) 08:21, 1 April 2011 (UTC)

Please have a look at the FAQ panel at the top of this page. Charles Matthews (talk) 08:31, 1 April 2011 (UTC)
It is not always easy to present technical material but if you come across a treatment that's more accessible, we can try to improve the wiki article as well. Tkuvho (talk) 10:43, 1 April 2011 (UTC)
I just had a look at the article and while there are a few things that could be tidied up it seemed to me to be on the better side as far as readability of maths articles goes. It is quite difficult remembering what problems one had learning something so probably the best thing to do is to flag the specific bits that first give trouble and the bits you find hardest to follow. Dmcq (talk) 11:09, 1 April 2011 (UTC)

The style/tone could also use some work there, e.g. Minsky exhorts the reader to be suspicious—although a machine may be finite, and finite automata "have a number of theoretical limitations": It reads like one of those controversial, he-says-she-says, social science articles. Tijfo098 (talk) 21:26, 1 April 2011 (UTC)

Absurd numbers

In view of the date, please have a look at this article and confirm my suspicions. JohnCD (talk) 19:07, 1 April 2011 (UTC)

It's a blatant hoax. I've marked it for speedy deletion. Sławomir Biały (talk) 19:14, 1 April 2011 (UTC)
Thank you, zapped. I just wanted a second pair of eyes. JohnCD (talk) 19:27, 1 April 2011 (UTC)

One of the more elaborate hoaxes. Created on the appropriate calendar date for such. Michael Hardy (talk) 22:40, 1 April 2011 (UTC)

I'm glad someone's watching. Still, I expect an interesting daily update tomorrow.  :-) Sławomir Biały (talk) 01:04, 2 April 2011 (UTC)

Subdirect product and Subdirectly irreducible algebra

Can anyone think of a reason not to merge these? Tijfo098 (talk) 22:36, 1 April 2011 (UTC)

Frobenius determinant theorem

Frobenius determinant theorem is a near-orphaned article. So if the internal-link-muse speaks to you, figure out which articles should link to it and add the links. Michael Hardy (talk) 22:37, 1 April 2011 (UTC)

Futurama theorem

Does the Futurama theorem merit its own article ? A merger proposal is being discussed at Talk:Futurama theorem. Gandalf61 (talk) 15:15, 2 April 2011 (UTC)

Tits group

The group of Jacques Tits is important in mathematics, and it might be a suitable article for this project to improve to Featured Status in time for next year's April Fool's Day.  Kiefer.Wolfowitz  (Discussion) 17:44, 2 April 2011 (UTC)

I think DYK would make more sense, but DYK's strange rules make this incredibly hard, even with the special April Fools exemptions for timing. Hans Adler 18:32, 2 April 2011 (UTC)
Eligibility for DYK would probably require some (other!) editors writing a fivefold expansion in a sandbox.  Kiefer.Wolfowitz  (Discussion) 19:35, 2 April 2011 (UTC)

There were a bunch of really obvious copy-editing issues that I've just taken care of. Michael Hardy (talk) 19:26, 2 April 2011 (UTC)

Simon Davis (mathematician)

Opinions of Simon Davis (mathematician)? It's been prodded. It says he applies the theory of perfect numbers to physics. I wouldn't have guessed those would be connected, but maybe I'm just naive. Michael Hardy (talk) 17:14, 2 April 2011 (UTC)

I started the article a long time ago; I don't think that I would start it now. His attempt to prove properties about OPNs via high-energy physics was a non-starter. CRGreathouse (t | c) 16:08, 3 April 2011 (UTC)

Ivar Ekeland

It would seem that we currently have no article about Ivar Ekeland, although nine other articles link to it. Michael Hardy (talk) 02:53, 3 April 2011 (UTC)

 Kiefer.Wolfowitz  (Discussion) 15:05, 3 April 2011 (UTC)
The German, French, and Spanish Wikipedias each have an article about him. Michael Hardy (talk) 14:56, 3 April 2011 (UTC)
That's helpful. (After the stressful shuttle-gossiping about the Monty Hall problem arbitration, I just have been writing about ridiculous topics, lately.) But I can translate the French article in a week or so.  Kiefer.Wolfowitz  (Discussion) 15:03, 3 April 2011 (UTC)

Tkuvho has now created the article and some others have contributed to it. Michael Hardy (talk) 19:35, 3 April 2011 (UTC)

Lead image of Pi

The article Pi is about the mathematical constant. There is a question about whether the lead image should be relevant to the topic of the article, or should be an image of the Greek letter. Please comment at Talk:Pi#Pi "Unrolled" animation. Sławomir Biały (talk) 19:41, 3 April 2011 (UTC)

If you have time while you're there, comments are being sought about moving Pi to π. Cheers, Ben (talk) 00:53, 4 April 2011 (UTC).

π (pi)

The usage of Π is under discussion, see Talk:Pi. (talk) 01:27, 4 April 2011 (UTC)

John Rainwater

Many of you will enjoy reading about John Rainwater, who led the functional-analysis seminar at the University of Washington over a 5-decade career. His research achievements and long-relationship with UW are remarkable especially given his graduate-student record, which included plagiarism and planting an explosive device for his professor. Sincerely,  Kiefer.Wolfowitz  (Discussion) 09:51, 2 April 2011 (UTC)

Note two related articles on other functional analysts, Robert Phelps and Peter Orno.  Kiefer.Wolfowitz  (Discussion) 02:34, 5 April 2011 (UTC)

Requested move of Fourth dimension

There's a request to move Fourth dimension to Four-dimensional space at Talk:Fourth dimension#Requested move Dmcq (talk) 00:52, 5 April 2011 (UTC)

Boolean algebra content forks?

We seem to have three articles on the same subject:

Does anyone know why? Are there any objective reasons to have three articles on this relatively elementary topic? — Carl (CBM · talk) 00:49, 29 March 2011 (UTC)

FWIW, I had redirected Boolean logic to Boolean algebra because (1) it was clear after doing my research for the lead for Boolean algebra that it's the same topic, and (2) there wasn't much in boolean logic that isn't in boolean algebra; Venn diagrams are in, and even google queries. The only thing that is not in are SQL queries, but there aren't conceptually different (not when restrcited to discussion about boolean operators), and there are thousands of programming languages (PL) out there, why SQL in particular? There's a CS-ish article on boolean expression that could cover that, but as you can see from its stubby nature, nobody (except StuRat) thought the syntactic difference in how boolean expressions are written in various PLs matter much. Tijfo098 (talk) 02:15, 29 March 2011 (UTC)
Enough reasons for merging Boolean logic yet again (!) can be seen at the talk page section Talk:Boolean_logic#Entire_Article_Rewrite and following section Talk:Boolean_logic#Problematic_article. Hans Adler pointed out at the time that StuRat was in violation of WP:OWN and WP:POVFORK. At the time StuRat had reverted the merging of his article by reviving it. Just now he's reverted Tijfo098's merge of it. In view of the many circumstances mitigating against this abysmally badly written article that StuRat owns, I've undone that revert. If StuRat wishes to reinstate his article a third time, we can offer him the choice of whether he prefers to be blocked for WP:OWN, WP:POVFORK, or WP:3RR. --Vaughan Pratt (talk) 03:26, 29 March 2011 (UTC)
Actually, StuRat promptly reverted my redirect, so I've started an official RfC on Talk:Boolean logic to attract opinion from previously uninvolved editors (and perhaps non-WPM editors as well to avoid some sort of systemic bias) as WP:DR recommends. Tijfo098 (talk) 05:55, 29 March 2011 (UTC)
Now, Boolean algebra (logic) needs more attention. There may be some material there worth merging (particularly the bibliography), but it seems too WP:NOTTEXTBOOK, e.g. explaining in detail how some expression is different if read as a Boolean rather than numeric. But even CS101 classes would give students a basic idea of type system. Tijfo098 (talk) 02:15, 29 March 2011 (UTC)
I do not own Boolean algebra (logic). It is true that I wrote more than 95% of it, but I have no objection to merging it with Boolean algebra. I'm all for anything to reduce the mess that the absurd proliferation of articles on Boolean algebra has become. --Vaughan Pratt (talk) 03:26, 29 March 2011 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── Actually, that article is well-written, so perhaps there is a way to keep it available to the public on WikiMedia servers. I don't now much about that, but I think Wikiversity would accept that page as-is. Although Wikiversity doesn't get the same google juice as Wikipedia, we could link it from Boolean algebra; I'm not sure what are the standards for that. Perhaps someone here has experience in that area? Tijfo098 (talk) 12:21, 29 March 2011 (UTC)

I was going to suggest as an alternative to move it to Introduction to Boolean algebra, but there's already yet another (introductory?) article on the same topic there. Actually, except for the lead, that article is nearly indentical to what Boolean algebra has now, so it's conceivable to move Boolean algebra (logic) over it. (Some care is needed to probably attributed the current content of [[bolean algebra, so, perhaps the current Intro should be moved to a subpage of Boolean algebra first.) Tijfo098 (talk) 09:48, 30 March 2011 (UTC)
I would guess it is in the natural order of things to delete Boolean algebra (logic) which (at first view) is subsumed by the new Boolean algebra as far as coverage is concerned and which extra details can be either added to the current "Boolean algebra" page or moved to specialized pages. However, it would be a pity to just dispatch its contents and delete it. So maybe, as it was suggested above by Tijfo098, that might be a good article to Wikiversity (that I don't know well actually how it works but that might be an alternative if some people think it is relevant). --Hugo Herbelin (talk) 20:19, 30 March 2011 (UTC)
There are several options:
I guess the second option would be best because that's an isolated page where it wouldn't be immediately surrounded by inferior stuff. Another option would be to move it to Citizendium. It doesn't have a Boolean algebra article yet. Of course in none of these locations it would get much attention. Hans Adler 20:46, 30 March 2011 (UTC)
The second option is fine by me. The upshot as I understand it is that Boolean algebra (logic) would (for now) become merely a redirect to Boolean algebra (later it might be expanded to Main article status parallel to Boolean algebra (structure). Its former text can go to wikiversity:Boolean algebra if that's kosher according to everyone involved. It's fine by me---as I said, although I wrote almost all of it, I don't own it, Wikipedia does. Or maybe it does: does Wikipedia continue to own text that has been deleted? There should be a mechanism whereby Wikipedia abandons deleted text after a suitable grace period in order to allow others to claim or reclaim it.
While on the subject of lightening up, I propose to put a merge tag on Boolean algebras canonically defined aimed at merging its source-able parts into Boolean algebra (structure) which is in dire need of more substantive material.
In the opposite direction, I'm considering writing a new article Boolean algebra (presentations) as a Main Article covering the many presentations of both Boolean operations (featuring in particular Post's completeness characterization as it appears in Boolean algebras canonically defined, along with complexity results about relative succinctness of different bases) and Boolean axiomatizations (featuring complemented distributive lattices and Boolean rings and why both are important, but also listing some of the more impressively succinct axiomatizations such as Huntington's axiom, Robbins's axiom, Wolfram's axiom, etc.). Boolean algebra is unusual among equational theories in having a great many presentations. Suggestions, objections, etc.? --Vaughan Pratt (talk) 00:57, 31 March 2011 (UTC)
Looking again at Boolean algebra (logic) I notice a section on derivation that could form the nucleus of another Main-article subtopic of Boolean algebra, namely Boolean algebra (proof systems) or something like that. --Vaughan Pratt (talk) 01:00, 31 March 2011 (UTC)
I think they should rather be called something like proof systems in Boolean algebra or presentations of Boolean algebras. If they're sourceable, that is, and not original synthesis. --Trovatore (talk) 01:09, 31 March 2011 (UTC)
I think that a List of equivalent definitions of Boolean algebras (or whatever the title) would be very useful and I would indeed recommend it to be not too much pure original research nor too much textbook-style (and possibly not at all of this kind). Such an article could typically also include non-equational, e.g. order-based presentations.
About a "proof system" article based on Boolean algebra (logic)#Derivations, I'm a bit skeptical. Part of this section should better go to a new page equational reasoning which (in my opinion inappropriately) links to universal algebra but which I think deserves both a larger and more operational approach, for instance by connecting it to rewriting.
I don't know what a more-senior-than-me wikipedian would say here, but my impression is that wikipedia also needs experts like you for consolidating the existing articles and for weaving more connections between articles. An easy road map in this direction would precisely be to merge the "canonically" article, without losing the technical content (creating e.g. an Examples of Boolean algebras subtopic) and ideally adding the new technical contents mentioned in previous discussions: atomicity, completeness, freeness, saturation. --Hugo Herbelin (talk) 23:11, 31 March 2011 (UTC)

FWIW, there is a book chapter in Padmanabhan & Rudeanu [38] (full ref given in Boolean algebra (structure)), so I have created Axiomatization of Boolean algebras as a redirect, but it's conceivable that it could become a list-type sub-article at some point. I don't have interest in developing it myself though. Tijfo098 (talk) 21:45, 1 April 2011 (UTC)

I'm not sure I understand what the purported proof systems article could contain that's not already in propositional calculus. Can someone enlighten me on that? Tijfo098 (talk) 21:57, 1 April 2011 (UTC)

Two-element one

There's a proposal to merge that as well at BATF. Tijfo098 (talk) 20:09, 6 April 2011 (UTC)


A. H. Lightstone is on sale here: Tkuvho (talk) 15:20, 31 March 2011 (UTC)

Could someone not involved in the discussion close it? Tkuvho (talk) 11:21, 5 April 2011 (UTC)
I wouldn't worry too much about that; it's linked to the appropriate daily logs, and the admins who patrol those logs generally close AfDs pretty punctually. —David Eppstein (talk) 15:58, 5 April 2011 (UTC)

Merge of subrandom numbers and Low-discrepancy sequence

I've proposed a merger of these articles at Talk:Subrandom numbers. It's not a merger that I myself feel competent enough to carry out, though. Are there any volunteers here? Sławomir Biały (talk) 11:51, 7 April 2011 (UTC)

New article Exact_Prime_Counting_Method

Could a mathematician take a look at this new article by a new contributor - it seems a bit odd to me but I don't know much about this subject.--Physics is all gnomes (talk) 13:31, 7 April 2011 (UTC)

It seems to be a very idiosyncratic version of the sieve of Eratosthenes. Sławomir Biały (talk) 13:46, 7 April 2011 (UTC)
The statement in the lead: "It works efficiently for infinitely large primes." with a reference citing a post on google groups [39] seems a bit dodgy. In fact, a lot of the article is a direct copy of that post, or vice versa. Is this saying anything useful or should it just be deleted?--Physics is all gnomes (talk) 13:55, 7 April 2011 (UTC)
(edit conflict) Somebody copied Sieve of Eratosthenes and threw in a little original research. It should be deleted. It references [40] by M. M. Musatov so I guess we have another addition for Category:Suspected Wikipedia sockpuppets of Martin.musatov. See Talk:Mersenne prime#For discussion for a disproof of his recent false claim [41] of discovering the largest known primes. PrimeHunter (talk) 13:57, 7 April 2011 (UTC)

Now proposed for deletion at Wikipedia:Articles for deletion/Exact Prime Counting Method. -- The Anome (talk) 14:26, 7 April 2011 (UTC)

Cool, thanks guys.--Physics is all gnomes (talk) 14:34, 7 April 2011 (UTC)


I have nominated Monty Hall problem for a featured article review here. Please join the discussion on whether this article meets featured article criteria. Articles are typically reviewed for two weeks. If substantial concerns are not addressed during the review period, the article will be moved to the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Delist" the article's featured status. The instructions for the review process are here. Tijfo098 (talk) 22:58, 7 April 2011 (UTC)

Cut locus

A somewhat odd and certainly under-referenced article. I looked it up after this thread, which is certainly enough to show the interest of this concept as basic geometry. (Of which I wasn't aware.) The corresponding Cut locus (Riemannian manifold) is better, but still looks neglected. Charles Matthews (talk) 15:54, 8 April 2011 (UTC)

Artin's c.........

Artin's conjecture on primitive roots and Artin's constant substantially overlap with each other. Each has a hatnote linking to the other. Should they get merged? Michael Hardy (talk) 03:19, 9 April 2011 (UTC)

It appears the latter article was created yesterday and seemed to be pretty much an exact copy of the former, so I'm just going to go ahead and make it a redirect again (also note that the hatnote at the former is *not* a link to the latter, rather it is a link to something entirely different also called "Artin's conjecture"). RobHar (talk) 04:03, 9 April 2011 (UTC)

Recommendation to delete an uneeded redirect for Template:Maths rating

I wanted to let you know I submitted a recommendation to delete an unused and probably uneeded redirect relating to template:Maths rating. You can see the request here. --Kumioko (talk) 19:53, 10 April 2011 (UTC)

Inappropriate language

Inappropriate language is being used at Tkuvho (talk) 11:25, 11 April 2011 (UTC)

If I understand that correctly, he's calling himself a moron. If he wants to do that, he's imho free to do so.--Kmhkmh (talk) 13:06, 11 April 2011 (UTC)
I think Nongendered added the "moron" sub-head when he responded to Leonid 2. It has now been removed by Staecker. Gandalf61 (talk) 13:14, 11 April 2011 (UTC)

Taylor series GAN

Taylor series, a top importance article, has been nominated for good article status (see WP:GACR for good article criteria). The review is here. We need reviewers and probably also editors. Sławomir Biały (talk) 18:18, 11 April 2011 (UTC)

Fuzzy matrix theory

Hi all,
I stumbled upon Fuzzy matrix theory, and it looked slightly odd and fringey. The sole source is this which looks rather like cargo-cult maths to me; so I've sent it to AfD. All expert inputs would be welcomed on the AfD page... alternatively, if it could be rescued somehow, that's cool too. bobrayner (talk) 21:48, 11 April 2011 (UTC)

Center of alternating groups

A4 is centerless

Until my revision the article Center (group theory) stated that

"The center of the alternating group An is trivial for n ≥ 5."

That may be true, but it sounds as if A4 had a nontrivial center, which is not true, as can be seen in the Cayley table on the right. So maybe it should read

"The center of the alternating group An is trivial for n ≥ 4."

If someone knows that's true he may add it to the article. Until now the sentence is <!---hidden--->. Lipedia (talk) 09:42, 13 April 2011 (UTC)

Another way to see it is that is the group of Euclidean rotations preserving the regular tetrahedron. Each non-identity element stabilizes a unique line through the origin, and these lines can be different from each other. Sławomir Biały (talk) 10:46, 13 April 2011 (UTC)

Wright Camera

Help. Trying to wikify Wright Camera (edit | talk | history | protect | delete | links | watch | logs | views) but, it needs some math expertise. Thanks,  Chzz  ►  05:58, 14 April 2011 (UTC)

Some Wikipedia talk:WikiProject Astronomy expertise would seem like a likelier choice to me. —David Eppstein (talk) 06:02, 14 April 2011 (UTC)

Proofs at Taylor's theorem

The article Taylor's theorem has a largish proliferation of proofs. (It used to have three, and has recently had as many as five. Now it's down to four. At least I've recently simplified two of those considerably.) I can see the usefulness of having some simple proofs that illustrate the basic relevant techniques (like the Cauchy mean value theorem, and restricting to a line segment in the case of several variables). However, there is some discussion of including complete proofs of basically all the results in the article. To me this seems rather contrary to the well-established consensus here, but I'd appreciate some outside input. Thanks, Sławomir Biały (talk) 22:47, 11 April 2011 (UTC)

I don't like the idea either. It's an encyclopaedia, after all, and not a mathematical text. References can be used for most proofs. Fly by Night (talk) 21:46, 13 April 2011 (UTC)
But we also have the "Wikipedia is not paper" argument, as long as a proof is not really impairing the structure of the article and introducing other problem, it isn't really much of problem and can be tolerated in doubt.--Kmhkmh (talk) 16:28, 15 April 2011 (UTC)

Circle (topology)

Circle (topology) currently redirects to circle group. Some knot-theory articles mentioning circles probably should link to circle (topology) but not to circle group. I've made circle (topology) into a "redirect with possibilities". So how about those possibilities? Should, or will, someone do something? Michael Hardy (talk) 03:11, 14 April 2011 (UTC)

I see the article circle group has a unique reference, by one Hua Luogeng. I don't have access to his book so I can't tell if he uses the term "circle group". Even if he does, does anyone else? Usually this is called the unitary group U(1). We should check into this being a neologism, and if so redirect it to one of the other pages. Tkuvho (talk) 04:37, 14 April 2011 (UTC)
I've definitely heard it called the circle group. RobHar (talk) 04:53, 14 April 2011 (UTC)
"Circle group" is common parlance - plenty of hits on MathOverflow, for example. Even more for "circle action". Charles Matthews (talk) 06:58, 14 April 2011 (UTC)
I see nothing wrong with circle group, but I doubt circle (topology) ought to target there, because the circle group is an algebraic rather than topological structure (or, if you see it as a topological group rather than just a group, at least it's as algebraic as topological). It might make sense to just delete circle (topology) unless there's some more canonical spot to retarget it. (Say, if we have an n-torus article, it could redirect there, to a section on the 1-torus.) --Trovatore (talk) 07:39, 14 April 2011 (UTC)
But when a knot-theory article refers to an embedding of a circle, where should the word "circle" link to, if not "circle (topology)"? Michael Hardy (talk) 14:18, 14 April 2011 (UTC)
Maybe it should redirect to unknot or vice versa. Tkuvho (talk) 14:28, 14 April 2011 (UTC)
Redirecting to unknot doesn't make sense. Whether a topological circle is knotted or not depends on how it is embedded in 3-space. The topological circle is the same topological space regardless of any embedding. Michael Hardy (talk) 17:52, 14 April 2011 (UTC)
N-sphere seems a good choice, it does cover the general topological idea and the specific instance of the 1-sphere.--Salix (talk): 14:30, 14 April 2011 (UTC)

I just found that circle action was a red link from quaternionic projective space, but nothing else linked there. So I redirected it to circle group. Michael Hardy (talk) 14:33, 14 April 2011 (UTC)

I don't think that's a good idea. A circle action is a much more common term than circle group. If anything it should be redirected to torus action. Tkuvho (talk) 14:35, 14 April 2011 (UTC)
Torus action currently redirects to toric variety. Michael Hardy (talk) 16:53, 14 April 2011 (UTC)
Add a few words to circle group to define "circle action", then. Kill off at least one of these. Charles Matthews (talk) 18:42, 14 April 2011 (UTC)

For now I've redirected circle (topology) to n-sphere, while leaving the "redirect with possibilities" tag intact. Michael Hardy (talk) 02:03, 15 April 2011 (UTC)

Also loop and free loop are related pages. Somewhere there should be a disambiguation of these. Tkuvho (talk) 04:45, 15 April 2011 (UTC)

Sub-Project for Prime Numbers

What about creating something like WikiProject Prime numbers. I know there is already the sub project Wikipedia:WikiProject Numbers, but I (and I think some other editors as well) are especially interested in prime numbers. The project could serve as a centralized point of discussion for editors interested in prime numbers, but not working on other number related articles. The scope of this project would include all of the articles about the classes of prime numbers listed in List of prime numbers. It could also include articles where the number class includes a subsequence of prime numbers that do not have an own article (like for example Leyland number). Toshio Yamaguchi (talk) 16:05, 14 April 2011 (UTC)

I'm very much interested in primes but I have no interest in articles like 97 (number). Is this proposed project for me or not? CRGreathouse (t | c) 16:45, 14 April 2011 (UTC)
Given that Wikipedia talk:WikiProject Numbers seems to be near-deserted, I think we should not create further subprojects. List of prime numbers contains <100 articles, many of which are stubby (and will remain so), so having a project for them seems unnecessary to me. Jakob.scholbach (talk) 16:48, 14 April 2011 (UTC)
The projects focus could be extended by including other articles related to prime numbers, such as Riemann hypothesis, Goldbach conjecture or Prime number theorem, just to mention a few. And is the fact that one WikiProject is (nearly) dead an argument against creation of a new WikiProject? Taking into account WP:OTHERSTUFFEXISTS I would say not. Toshio Yamaguchi (talk) 17:11, 14 April 2011 (UTC)
OK, but <1000 articles even link to prime number. Creating a project with such a small scope requires time and energy that might better be spent otherwise. For example, bring prime number to GA status?! Jakob.scholbach (talk) 19:35, 14 April 2011 (UTC)
(ec) There is an ideal size for WikiProjects, and it's pretty close to the current size of WikiProject Mathematics. It's the size where communication on the project talk page actually happens. I.e. everybody finds the time to read everything, and that's not because almost nothing ever happens. WP:WikiProject Logic is an example for a WikiProject that is almost dead because it is too small. Your proposed WikiProject would be so tiny as to be almost certainly completely useless. Project space is full of the se attempted microprojects. See WP:WikiProject Mathematical and Computational Biology for a recent example (where I commented in more detail on the problem). Hans Adler 19:37, 14 April 2011 (UTC)
I agree with the points given. It should really be possible to handle it through this WikiProject. Toshio Yamaguchi (talk) 19:44, 14 April 2011 (UTC)
I tend to think that WikiProject Mathematics is not just larger but *far* larger than optimal for a WikiProject. Its success at this size is atypical, I think. (That's not to say that the proposed project would be large enough to work!) CRGreathouse (t | c) 19:55, 14 April 2011 (UTC)
WPM is large in terms of articles but not that big in terms of active members. A split might not hurt but I don't see what's broken that we need to fix. For example this page isn't overwhelmed with posts and we've done a good job with organizing articles so people can find articles to work on in areas they're interested in.--RDBury (talk) 04:55, 15 April 2011 (UTC)
Point of information: I believe the Wikipedia term for a 'sub-project' is a WP:Task force. That might be more appropriate than an entire new WikiProject. --Qwfp (talk) 07:09, 15 April 2011 (UTC)
I might have proposed that as well, but even a task force should start with the momentum of a bunch of editors who want to work on a task. I am not seeing this (yet?) in the present case. Hans Adler 07:31, 15 April 2011 (UTC)
I would like to participate in that task force, if created. Toshio Yamaguchi (talk) 15:58, 15 April 2011 (UTC)

edits by Gustave the Steel

At Talk:0.999... inexperienced editors sometimes leave comments that are not directly related to improving the page. For this reason, a separate "arguments" page was created where such discussions can continue. Comments not directly related to improving the page are supposed to be moved to the "arguments" page. Recently, a couple of editors started a new trend of summarily deleting comments that are not to their liking. Furthermore, one of them threatened to "report" any further reinstatement of the deleted material. This would not appear to be consistent with minimal standards of politeness we expect at wiki. Tkuvho (talk) 04:42, 15 April 2011 (UTC)

I would suggest this is the sort of thing that is better solved by personal discussion, rather than a mass announcement. — Carl (CBM · talk) 01:45, 16 April 2011 (UTC)

Euler on infinite series

Euler on infinite series has been prodded for deletion. (talk) 04:58, 15 April 2011 (UTC)

The topic is probably worth an article, but the present content of the article fails to demonstrate that. Michael Hardy (talk) 15:54, 15 April 2011 (UTC)

Derivations in articles (again)

I'm actually coming back to this as a result of some discussion at Talk:The Prisoner of Benda (where the ridiculous suggestion that minor copyedits to a proof were "original research"). In the past, we've had many discussions on inclusion of proofs in articles, and now there is even the dedicated subpage Wikipedia:WikiProject Mathematics/Proofs. A basic editing principle that I have always adhered to is that it's better just to say why a result is true than to give a detailed derivation of it. This often means communicating the main ideas of the proof, without going into details. (In some sense, to "talk about the proof" rather than give it.) I find that this produces more seamless prose suited to an encyclopedia article. I've always thought that somewhere this was codified in a guideline or essay. It's certainly a point that I bring up in most discussions about proofs in mathematics articles. But it doesn't seem to be in either WP:MSM or WP:WPM/Proofs. Is this idea, or something like it, something we agree on? Should it be added to WP:WPM/Proofs? Sławomir Biały (talk) 11:47, 13 April 2011 (UTC)

Addendum: There's this is WP:MTAA: "For example, a detailed derivation of a result is unlikely to be read by either a general reader or an expert, but a short summary of the derivation may convey a sense to a general reader without reducing the usefulness to an expert reader." Sławomir Biały (talk) 12:08, 13 April 2011 (UTC)
In principle I agree with your suggestion. I'm undecided, though, whether this should be hard-coded into a guideline. Especially because surveying hard proofs in this way can be much more difficult than following them in a more detailed manner. Jakob.scholbach (talk) 15:42, 13 April 2011 (UTC)
The French WP has elegant proofs that can be expanded with a touch of a button.


(The French write so elegantly!) 17:20, 13 April 2011 (UTC)
I think this also depends on ther context and scope of the proof in question. Occasionally giving the actual proof might be more accessible/faster to comprehend for readers than writing about it. But the biggest area of conflict (with non math editors for the most part) will be OR complains, so we should codify somewhere explicity that shortening/summarizing a (sourced) proof is not OR.--Kmhkmh (talk) 21:26, 13 April 2011 (UTC)

The editor at Talk:The Prisoner of Benda has become increasingly aggressive in his stance that summarizing published proofs and making slight copyedits to them is original research. I would appreciate it if someone uninvolved could have a look. Sławomir Biały (talk) 13:13, 14 April 2011 (UTC)

This is a very liberal interpretation of the claim I'm making. The issue is that the proof in question isn't really a published proof at all, but a screenshot from a TV episode. Andrevan@ 14:30, 14 April 2011 (UTC)
You've been warring to remove a section against consensus based on a tendentious interpretation of policy. You should know better. Sławomir Biały (talk) 14:42, 14 April 2011 (UTC)
I hate to pull rank, but I do know better. I've been an admin on Wikipedia for almost 7 years. My argument is legitimate in the context of core content policies concerning verifiability, reliability, and original research. You may disagree with my interpretation, but you must assume good faith. Andrevan@ 15:14, 14 April 2011 (UTC)
More browbeating. I'm glad that, in reality, admins don't have any special status when it comes to interpretation of policy. It's pretty clear you have no idea how to correctly apply core policies to technical content, I'm sorry to say. Sławomir Biały (talk) 15:22, 14 April 2011 (UTC)
I think your use of the phrase "More browbeating" is strange, previously used by Gandalf61[42] and Protonk[43], two other participants in the original discussion. I don't understand what you are accusing me of. Andrevan@ 16:08, 14 April 2011 (UTC)
You refuse to participate in any constructive process or discussion. On the discussion page, you accuse everyone else of misunderstanding policy, rather than respond substantively to the points made there. (I "don't understand synth", I " don't understand how citation needed tags work", etc.). You maintain an editing environment that is hostile to anyone who disagrees with you, and exhibit ownership of the article. Should I go on? Sławomir Biały (talk) 16:20, 14 April 2011 (UTC)
I believe what I'm doing is constructively participating in the discussion. You may disagree with me, but there's nothing wrong with the way I'm going about it. I stand by the statement that your position on the issue does not exhibit understanding of the core policies on synthesis and verifiability. I would also add that you don't understand WP:OWNERSHIP, which refers to being possessive about material that was added. In this case, I believe the material should be REMOVED! This isn't browbeating, this is simple policy argument. Andrevan@ 16:26, 14 April 2011 (UTC)
Reverting to earlier versions despite consensus, trying to trump that consensus with obviously tendentious interpretations of policy, certainly interpretations unsupported by long-established best practices. Please, someone get involved and put a stop to this idiocy. Sławomir Biały (talk) 16:34, 14 April 2011 (UTC)
I believe that was a personal attack. Andrevan@ 16:36, 14 April 2011 (UTC)
Umm... What was? Calling this episode "idiocy"? I suppose you'd better block me. You are an admin, after all, as you're so fond of pointing out. Sławomir Biały (talk) 17:08, 14 April 2011 (UTC)
The use of "idiocy" is certainly a personal attack. Obviously I'm not going to block you, simply advise you to take a step back and consider your words more carefully. Andrevan@ 23:05, 14 April 2011 (UTC)
Andrevan has started an RfC at Talk:The Prisoner of Benda. Sławomir Biały (talk) 15:07, 14 April 2011 (UTC)

I think this ridiculous episode makes it glaringly obvious that we need clarity on whether summarizing proofs, or rewriting proofs in our own words without substantively altering them, or changing notation, is considered to be original research. It is painfully clear to me that, in the case of discussion, no original research has been committed at any time, in any version of the article under discussion. It has already been (convincingly, to my mind, by Kmhkmh), suggested that Andrevan has been misrepresenting the spirit, if not the letter, of WP:OR by insisting on an overly rigid interpretation of it. Also, a lot of this is explained by the fact that Andrevan is of the opinion that WP:V means that a lay-person should be able to verify the content of an article, without requiring any special subject knowledge. This is an untenable position for any encyclopedia that covers a wide range of serious topics, in my opinion. But there it is. Perhaps we need to formalize some clarity about that as well. Sławomir Biały (talk) 00:14, 15 April 2011 (UTC)

Somewhat, off-topic: I agree that some editors have ridiculous views as to what constitutes original research, even for WP purposes. Someone complained at the FAC for logarithm that assembling list of examples, all of which can be individually sourced is WP:OR. Duh, ... We do have WP:SCICITE to "hit them back" with, but of course, it's only a guideline, so if someone is hell bent on rules lawyering... Tijfo098 (talk) 07:17, 17 April 2011 (UTC)


May be a little off-topic here, but I don't know where else to ask. Can someone figure out what's the deal with Birkhäuser Verlag vs. the Springer math & science book series, which is still published under that imprint? We might need to create a dab for Birkhäuser. Tijfo098 (talk) 06:51, 17 April 2011 (UTC)

Answered at Talk:Birkhäuser Verlag.  --Lambiam 19:52, 17 April 2011 (UTC)


Blackburne, of A. H. Lightstone fame, is now attempting to delete a brief quotation at Adequality on the grounds that it is a copyright violation. Help! Tkuvho (talk) 12:24, 17 April 2011 (UTC)

Gopala–Hemachandra number AfD

There is a deletion discussion for this article which is getting a lot of attention. This is related to Fibonacci number which is #7 on our list of most frequently viewed (really more like #1 if you take out physics and statistics articles).--RDBury (talk) 18:10, 17 April 2011 (UTC)


Can someone improve Heinz-Dieter Ebbinghaus before it's nominated for deletion? Tijfo098 (talk) 09:12, 18 April 2011 (UTC)

Clause (logic)

Maybe someone here has an opinion whether clause in logic only means a disjunction. Tijfo098 (talk) 16:14, 18 April 2011 (UTC)

DYK? for Ivar Ekeland (21 April)

The DYK nomination for the new article on Ivar Ekeland, which Tkuvho started (and which I expanded) should get a lot of DYK hits.

A picture of the Julia set

  • ... that, by writing about chaos theory and fractals (like the Julia set, animated), mathematician Ivar Ekeland helped to inspire Jurassic Park by Michael Crichton and Steven Spielberg?

A picture of the Feigenbaum bifurcation of the logistic function.

  • ... that, by writing about chaos theory and fractals (pictured), mathematician Ivar Ekeland helped to inspire Jurassic Park by Michael Crichton and Steven Spielberg?
 Kiefer.Wolfowitz  (Discussion) 19:45, 13 April 2011 (UTC)

5x expanded by Kiefer.Wolfowitz (talk). Self nom at 10:55, 12 April 2011 (UTC)

The DYK? appearance shall be 21 April, alas, without a picture. (An Easter topic will have an illustration.)  Kiefer.Wolfowitz  (Discussion) 22:17, 19 April 2011 (UTC)

Non-Newtonian calculus

There's a number of links to non-Newtonian calculus being stuck in to various articles by User Talk:Smithpith (contribs). He has warnings in the talk page but we should figure out exactly what link should be kept if any I think. Dmcq (talk) 20:02, 18 April 2011 (UTC)

I'm sure that this has been a topic of discussion a long while ago. I don't remember what the outcome was. Is there a way to search the project's archives? Fly by Night (talk) 22:00, 18 April 2011 (UTC)
The story is quite sad. A number of non-mathematically educated users protested the AfD for non-Newtonian calculus and multiplicative calculus, and they were kept. The articles have been a stain on Wikipedia ever since. As a rule I try to make sure that nothing links to them; giving them any prominence amounts to WP:UNDUE, and even if they were notable, Smithpith links other articles to them much too heavily. (Smithpith has also in the past admitted to being Michael Grossman, the co-inventor of non-Newtonian calculus). I've cleaned up again; but the long term solution is to delete these articles once and for all. Ozob (talk) 22:34, 18 April 2011 (UTC)
Having said that, it does seem to have almost 80 publications as supporting references. What is to be made of that? Has anyone checked the validity of the references? Fly by Night (talk) 01:02, 19 April 2011 (UTC)
At the time of the AfD, I checked all of the references that were then in the article. It appeared that Mr. Grossman had cataloged every mention ever made of his book. Frequently these were advertisements he had placed, and most of the rest were in lists of recently published books.
In retrospect, I was quite wrong. Mr. Grossman had not nearly cataloged every reference ever made to his work. He has industriously remedied that defect, and the article now has, as you say, almost eighty references. The article even tells you what kind of references they are: His book is "mentioned" or "reviewed" over and over. The prominence of "mentions" and "reviews" in that list and the relative scarcity of citations evinces the yawn with which the book has been received. But there are so many references I fear they will win over the voters at an AfD discussion. I think a successful AfD would have to be done carefully and with much support from this WikiProject. Ozob (talk) 01:54, 19 April 2011 (UTC)

From Michael Grossman: I thought those links were pertinent. If I was wrong, I'm sorry. I have no intention of violating Wikipedia's rules. Smithpith (talk) 22:58, 18 April 2011 (UTC)

Wikipedia is not XXXXX. Kevin Baastalk 01:10, 19 April 2011 (UTC)
I removed the personal attack by Baas, leaving XXXXX instead.  Kiefer.Wolfowitz  (Discussion) 19:43, 19 April 2011 (UTC)
This comment seems very inappropriate. I have no idea what it's supposed to convey. Sławomir Biały (talk) 14:41, 19 April 2011 (UTC)
To Kevin Baas: Your comment seems to imply that you think that someone here has been acting like a Nazi. If made explicit, that would be considered a personal attack on that person. Left cryptic as it is, it unfairly impugns everyone in this dispute who disagrees with you. JRSpriggs (talk) 19:26, 19 April 2011 (UTC)

Images for articles about integer sequences

I created an infobox for articles about integer sequences a while ago (see Template:Infobox integer sequence for the template and Special:WhatLinksHere/Template:Infobox integer sequence for articles, where it is currently being used). I would like to include an image in every case, where the infobox is in use. For this purpose, it would be nice to have some input on which ways of visualizing integer sequences could be used for creating images for use in the infobox. My preference is in favor of ideas that can be easily realized using simple image editing software. Also I am aware of the visualization methods used by OEIS. Finally, the image should be interesting, without being distracting, even if only two or three terms of the sequence are known. Any additional input is welcome. Thanks. Toshio Yamaguchi (talk) 23:07, 18 April 2011 (UTC)

While we can always use more and improved images, mathematical concepts are often too abstract for an image to have any meaningful value. For example one of the articles that uses the template is Mersenne prime and I have a hard time seeing how an illustration would help make the concept more understandable. There are exceptions such as Ulam spiral for primes and Fibonacci spiral for Fibonacci numbers, but I don't think finding an image for every article is realistic. Perhaps it would be better to concentrate on adding the template to more articles since at the moment it's only used in 7.--RDBury (talk) 14:46, 19 April 2011 (UTC)
Neil Sloane recently changed the legal status of OEIS. Are the images released under a compatible license with ours? That might present the easiest solution if so. If not, Sloane can probably be persuaded to release the media under the CCA license if we think that's worth pursuing. Sławomir Biały (talk) 14:51, 19 April 2011 (UTC)
From here (see bottom of the page) and here it seems they are licensed under a Creative Commons Attribution Non-Commercial 3.0 license. From what I know this is incompatible with a use on Wikipedia, since our terms allow commercial use. So if there were any chance to use them, we would have to do under our guidelines related to WP:FAIRUSE. Toshio Yamaguchi (talk) 15:15, 19 April 2011 (UTC)
On the other hand I am unsure if the images are eligible for copyright at all per the concept of Threshold of originality. Toshio Yamaguchi (talk) 15:48, 19 April 2011 (UTC)
Licensing aside, Dr. Sloane's image probably isn't appropriate here. It's meant to represent that encyclopedia, not the general concept of an integer sequence. CRGreathouse (t | c) 19:53, 20 April 2011 (UTC)
It seems to me that the proposal is to have a different image for visualization of each integer sequence. Sławomir Biały (talk) 20:05, 20 April 2011 (UTC)
Yes, exactly. A different image for each sequence. Toshio Yamaguchi (talk) 23:31, 20 April 2011 (UTC)

Error term

....currently redirects to errors and residuals in statistics. That obviously doesn't make sense. So:

  • Disambiguation page?
  • Different redirect?
  • Article?
  • whatever..........?

Michael Hardy (talk) 19:31, 19 April 2011 (UTC)

I searched Wikipedia for "error term" and found that the statistical usage is much more common than all other uses combined. So if you decide to make a disambiguation page, then it should be listed first. Another use was for the Big O notation. JRSpriggs (talk) 19:47, 19 April 2011 (UTC)
To me an error term is a term representing the difference between the exact value of something and the approximate value given as some function (as in Taylor's theorem, where the error term is also called the remainder term, or in asymptotic results such as average orders of arithmetic functions). Often the error term isn't known that well, but a bound is known, which is the relation to Big O notation. I was pretty sure that on a measurement the error was simply called the "error", not the "error term", what do you mean by the "statistical usage"? RobHar (talk) 22:22, 19 April 2011 (UTC)
By "statistical usage" I meant the use of "error term" to refer to the observational error discussed at errors and residuals in statistics where it is called just "error". None the less, it is called "error term" in many of our articles, presumably because it is a term added to the theoretical value to get the measured value. JRSpriggs (talk) 07:35, 21 April 2011 (UTC)
I've usually seen it in connection with analysis (like Taylor's theorem) or numerical analysis. Redirecting it to statistics seems a little bit odd to me, but I don't have a firm opinion. (talk) 09:40, 21 April 2011 (UTC)

Proposal to move Non-Newtonian calculus to Modifications of the calculus

I propose to move the controversial page Non-Newtonian calculus to a more appropriate title Modifications of the calculus. It can be decided later what to do about multiplicative calculus. The term "non-Newtonian" is a neologism coined by the author of the book that has not been widely accepted. The term makes it appear as if this approach is a significant modification of the calculus, somehow going against the Newtonian approach. Meanwhile, the main idea of this approach seems to amount to apply log to a product before differentiating. Whatever the possible applications of this method may be in engineering, the title should reflect the contents more precisely. Also in any future AfD the participants will have a more accurate picture of the intrinsic merit of the approach. Tkuvho (talk) 10:09, 21 April 2011 (UTC)

WP:TITLE says that, in general, an article's title should be "what reliable English-language sources call the subject of the article". So if the widely accepted term for the subject of this article is not "non-Newtonian calculus", then what is it ? "Modifications of the calculus" sounds both clumsy and vague - unless there is a source for this alternative title, are you not in danger of replacing one neologism by another ? Gandalf61 (talk) 10:24, 21 April 2011 (UTC)
No, this is not a new neologism, because the new title is meant to be descriptive. You claim that the name "non-Newtonian" is "widely accepted", but one of the editors above claims that the theory has received a lukewarm response and almost ignored. My main point is that the "non-Newtonian" business is very misleading, as it implies some major foundational innovation. Such an innovation is just not there. I looked up their 1972 book. In the introduction they claim that their theory is "very different" from that of Newton and Leibniz. How many people believe that? Tkuvho (talk) 10:55, 21 April 2011 (UTC)
But the article is "about" the 1972 book more than anything else. I don't think we should have an article about this book, given the utter lack of meaningful critical response, but it already survived an AfD since folks were duped by the number of references. Also, there are (presumably) other modifications of the calculus (nonstandard calculus, for instance), and just moving this article would be giving grossly disproportionate coverage to one (rather nonnotable) such modification. I would advocate simply redirecting the article to multiplicative calculus. Neither article is good, but I'd rather have one bad article than two. Sławomir Biały (talk) 11:15, 21 April 2011 (UTC)
Other editors (in a subsection above) have similarly expressed the sentiment that the article is not notable, and also noted the difficulty of succeeding in an AfD. My point is that such difficulty is exacerbated by a misleading title, which might lead inexperienced editors to oppose deletion of what is presented as some kind of revolutionary alternative to Newton. I think the title "multiplicative calculus" is similarly misleading, as it suggests that we have some kind of a new calculus here. "Modification" seems to be the right description; whether or not such a modification is notable can be determined in a future AfD. Tkuvho (talk) 11:28, 21 April 2011 (UTC)
The place to take notability concerns is clearly AfD. The previous AfD on Non-Newtonian calculus was over 2 years ago, so a long enough interval has elapsed for a second AfD. Present your arguments in a clear way that even those pesky "inexperienced editors" can understand, and establish consensus through discussion. FWIW, my view is that changing an established article's title in place of or before an AfD seems awfully close to gaming the system. Gandalf61 (talk) 11:51, 21 April 2011 (UTC)
A potential AfD is a separate issue. The current grandiose title is a neologism that has not been widely accepted. I am proposing a more modest title that's descriptive of the contents. The current grandiose title games the system in favor of a potentially unnotable article. Tkuvho (talk) 12:18, 21 April 2011 (UTC)
The title of the article says nothing about its notability. It merely, describes the subject in the term most commonly used to describe the subject by people that talk about the subject. Your argument seems to be that almost nobody discussed this subject, that could very well be, but that is an argument for deletion not renaming. If you want to rename the article, you will have to provide some evidence of sources discussing this subject, which do not call it non-Newtonian calculus.
(And just for the record your proposed new name for the article is grammatically flawed.) TR 12:38, 21 April 2011 (UTC)
Suggestion: move it to Non-Newtonian Calculus, and add {{italictitle}}. Then the introduction would be modified to make it refer just to the book of that name. That way, it is clear that it is the authors' choice of phrase. Otherwise you would have to have something cumbersome like Grossman and Katz modifications of calculus. Xanthoxyl < 12:54, 21 April 2011 (UTC)
Good idea - Non-Newtonian Calculus, italicised in line with WP:MOSTITLE, is clear and unambiguous. Works for me. Gandalf61 (talk) 13:35, 21 April 2011 (UTC)
Since it's clear that this article is primarily about the book, it's high time that it go back to AfD. This is not a notable book, receiving only 19 citations on Google scholar (five of which are self-citations). Sławomir Biały (talk) 13:42, 21 April 2011 (UTC)
I agree that the italic version might be a move might be a good idea. One could also consider to the term in quotes or qualifiers in the article itself (for the first bold print). But moving it to Modifications of the calculus is not a good idea for the reasons stated Sławomir Biały & Gandalf61. The appropriate way to deal with a (unnotable) neologism is an AfD. If that fails we will have to live with neologism. However we still can indicate the neologism/lack of notability character in the article itself by using qualifiers and insisting on intext attribution wherever it maybe reasonable, but we should not change the name to something which isn't really used in the sources or by the few people actually refering to it.--Kmhkmh (talk) 13:52, 21 April 2011 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── The article has been nominated for deletion: Wikipedia:Articles for deletion/Non-Newtonian calculus (2nd nomination). Please direct your comments there. Sławomir Biały (talk) 14:38, 21 April 2011 (UTC)

Are the proposed & rejected "Modifications" all standard in contrast to non-standard calculus following Abraham Robinson and exemplified by Jerome Keisler's introductory textbook? (I have reorganized the lead of that article but it will benefit from further rewrite. I have only slightly addressed the criticisms by myself and others. See multiple sections of Talk:Non-standard calculus.) --P64 (talk) 19:12, 21 April 2011 (UTC)
It has nothing to do with non-standard calculus, I believe yes is the answer to your question though of course one could always develop 'standard' calculus using non-standard calculus - that's what a lot of it is about! Dmcq (talk) 22:24, 21 April 2011 (UTC)

List of numeral systems

I've created List of numeral systems and would appreciate help making it somewhat complete. --Beao 17:36, 21 April 2011 (UTC)

Radio 4 mathematics collection

The BBC has a collection of audio programs related to mathematics at [44]. Many of these are episodes of the radio series "In Our Time". Just mentioning it for general interest but I'm also thinking it would be a worthwhile project to make sure we have a link to each program in the "External links" section of the corresponding WP article.--RDBury (talk) 17:38, 20 April 2011 (UTC)

Update: I added links to five of the "In Our Time" episodes so all are done except "Renaissance Mathematics" for which we don't have an article, just a section in History of mathematics.--RDBury (talk) 03:36, 21 April 2011 (UTC)
Thanks for posting those links. I listened to most of them. I even forwarded the infinity one to a couple of non-mathematical friends. It's funny though. In all of the attempts to simplify maths for a general audience, I always find that the result loses all of its beauty. For me, the complexity and the structure of maths is what makes it so interesting. Sadly, some of those links perpetuated the myth of mathematicians solving equations all day. There were lines like "Mathematicians love numbers because…", and they interpreted Chaitin's constant as meaning that there are "infinitely many unsolvable equations." But, hey. what can we do? Once again, thanks for linking to those radio programs. Fly by Night (talk) 20:55, 22 April 2011 (UTC)

Radius one or diameter one in circle rolling

I'm looking for reactions to the idea at File talk:Pi-unrolled-720.gif#Radians. In a nutshell, the idea is to make a relatively minor change to that animation changing the radius from 1/2 to 1 and the circumference from π to 2π (I don't really know whether this would be controversial, but at least to me the reasons for it are pretty sound and in line with the mathematical tendency to deal with circles of radius one). The intro (where it lines up the circles) would probably best be changed to somehow visually emphasize the radius a bit more than the diameter. Whether the new image replaces the old one or just gets used places like Radian and Turn (geometry) is to be determined. If people like the idea, we can presumably get help from Wikipedia:Graphic Lab/Illustration workshop and/or Wikipedia:Graphic Lab/Photography workshop (I would have thought the former, but I guess the people at the latter are more accustomed to working with raster images). Kingdon (talk) 01:33, 23 April 2011 (UTC)


I expect most of us who have math articles on our watchlists see this from time to time -- an article contains the word provably, used correctly, and someone, usually an IP, changes it to probably.

I was just idly wondering if anyone else has an opinion on this. Is it a specific person who just likes to do this for fun, maybe figuring it's a subtle change that might escape notice? Or, is it that a lot of people just don't know the word provably and fix the "typo" in good faith?

Either way, it seems likely that some such changes go uncaught. Just thought I'd mention it so that the next time one of us sees the word probably in a math article, we might give half a second's thought to whether it's really supposed to be provably. (Or, I suppose, the reverse is also possible, but I don't recall an example of that.) --Trovatore (talk) 04:56, 23 April 2011 (UTC)

I think the people who do it are honestly confused. I would expect that some spellcheckers don't know the word. And as Spanish speakers tend to conflate v and b it's actually plausible as an error. Hans Adler 16:05, 23 April 2011 (UTC)
Suggest that when "provably" is used, it is linked to a definition (something on the Proof page, probably (no pun intended)).
On our (ugly) sister site ProofWiki we have the same problem with getting "iff" changed to "if" so whenever I see this I change it to a specific link to a definition of "iff" as I can't abide "if and only if". --Matt Westwood 05:18, 23 April 2011 (UTC)
It's a bit of a tangent, but I (for one) can't abide "iff" in formal writing such as we should be using on Wikipedia. I'll happily use it on talk pages and other less-formal contexts. MOS:MATH agrees (see the section "Writing style in mathematics"). So unless you want to build consensus to get the MOS changed, please just spell it out. (Also, I am a victim of the provably/probably thing — one of my papers uses "provably" in the title and it has occasionally been cited as "probably".)—David Eppstein (talk) 05:31, 23 April 2011 (UTC)
I agree. By my standards iff is properly confined to blackboards or quick notes; its only function is to be able to be written quickly. I also don't agree with linking it (or provably). Links are primarily intended to enable in-depth reading on an important aspect of the topic being read. I dislike links whose main purpose seems to be to say "hey, this is a word I'm not sure you know". --Trovatore (talk) 07:26, 23 April 2011 (UTC)
Just to set you all straight, I'm not talking about Wikipedia here, I'm not suggesting "iff" be used on this site, that would indeed be outrageous. I was talking about what we do on ProofWiki where the rules are different because we're doing a different job.
I replied to this post because I was able to offer a suggestion as to what to do in this circumstance. But okay, if the page uses a word which confuses people enough to want to change it "because it's obviously wrong", then you definitely need *some* sort of means to tell the reader: yes I *do* mean that word.
So, a further suggestion: how about a link to Wiktionary? --Matt Westwood 09:33, 23 April 2011 (UTC)
As for "provably", there are probably many cases where it can be dropped altogether. E.g. "The set of prime numbers is provably infinite." -> "The set of prime numbers is infinite." There are variations that might also cause confusion, "provable" vs. "probable", "provability" vs. "probability", and these might be more difficult to deal with. Perhaps in such cases a hidden comment can be added such as <!-- Please leave spelling as is. -->. If we start adding links every time there is a word someone might not understand the articles will fill up with distracting link symbols. Someday someone will add a browser feature where clicking any word will look it up for them on their favorite on-line dictionary; we shouldn't try to implement it here.--RDBury (talk) 15:52, 23 April 2011 (UTC)
I recommend {{not a typo|provably}}. I think that's the "official" way to mark something as "meant". -- John of Reading (talk) 16:27, 23 April 2011 (UTC)
That looks good. Thanks! --Trovatore (talk) 17:03, 23 April 2011 (UTC)

Haynsworth inertia additivity formula

I've created a new article titled Haynsworth inertia additivity formula.

That article and Sylvester's law of inertia treat of this particular concept of "inertia". Is this so called because of a conceptual connection with physical inertia? If so, those article ought to explain the connetion.

To do:

  • Explain that connection.
  • Otherwise improve the article.
  • Link to the article from appropriate other articles.

Michael Hardy (talk) 18:07, 23 April 2011 (UTC)

The connection is the inertia tensor, for what it's worth. Sławomir Biały (talk) 20:44, 23 April 2011 (UTC)
Thank you. I wouldn't mind if some linear algebra textbooks at least mentioned that when they mention the word "inertia". Michael Hardy (talk) 00:33, 24 April 2011 (UTC)

List of matrix topics?

Should we have a list of matrix topics or list of matrix theory topics? Michael Hardy (talk) 18:15, 23 April 2011 (UTC)

Navboxes are more useful than lists particularly for slow connections. You can see a navbox without downloading another page. Also, navboxes can be structured and thus carry more information than alphabetic lists. Tkuvho (talk) 21:39, 23 April 2011 (UTC)

But navboxes seem to be for navigating, whereas lists are (partly? largely?) for browsing. Michael Hardy (talk) 00:29, 24 April 2011 (UTC)

Does Category:Linear algebra help? (talk) 00:38, 24 April 2011 (UTC)
Not really. It's merely a category, not a list. List of linear algebra topics is somewhat more to the point. Michael Hardy (talk) 04:21, 24 April 2011 (UTC)

Branching random walk

Branching random walk is a stubby new article. Work on it. Michael Hardy (talk) 21:03, 22 April 2011 (UTC)

Good luck! Shouldn't it be "branching random-walk", per MOS?  Kiefer.Wolfowitz  (Discussion) 22:00, 22 April 2011 (UTC)
In most cases, modifiers right-associate by default, and you need hyphens only to mark exceptions from that. --Trovatore (talk) 22:02, 22 April 2011 (UTC)
My reading of the MOS, and my discussion of "real vector-space" with MF, suggests that the MOS mandates recommends the suggested hyphenation, which is consistent with Michael Dummett's book.
I already moved the page. However, "anybody attempting to use hyphens consistently shall go mad"!  Kiefer.Wolfowitz  (Discussion) 22:25, 22 April 2011 (UTC)
OK, I totally disagree with that move. Kiefer, are you a native speaker? To my ear/eye/whatever this hyphen is very jarring. Who is MF, and where do you see this in the MOS? --Trovatore (talk) 23:36, 22 April 2011 (UTC)
Totally see my user page for information about me. For MF, search among the primary writers of featured articles on English WP. See the MOS, also.  Kiefer.Wolfowitz  (Discussion) 23:42, 22 April 2011 (UTC)
I don't see on your user page where it says whether you're a native speaker of English. Oh, never mind; it was under a "show". You claim to have a "professional" level of English. This is not the same as having a native ear. How about just answering the question about MF rather than telling me where to search? Please point me to the clause in the MOS on which you're relying. --Trovatore (talk) 23:49, 22 April 2011 (UTC)
Sweden has a number of probabilists analyzing branching processes and random walks. Perhaps it is not obvious that branching modifies "random walk"?  Kiefer.Wolfowitz  (Discussion) 23:46, 22 April 2011 (UTC)
What else is available for it to be modifying? --Trovatore (talk) 23:49, 22 April 2011 (UTC)
The MoS doesn't mandate using a hyphen in every compound attributive, and it gives some examples where adding a hyphen changes the meaning. I would say that in "branching random walk", a hyphen is not needed because it is clear that "branching" modifies "random walk", rather than "random". By contrast, a hyphen would be necessary if we meant "branching-random walk" (whatever that could mean). A simpler example: we wouldn't write "hot chicken-soup" (to mean chicken soup that is hot), but we would need to write "hot-chicken soup" (soup made out of hot chickens). Sławomir Biały (talk) 23:58, 22 April 2011 (UTC)
Sławomir, "branching" modifies the object "random walk". The problem for civilians is that "branching", like "halting", could modify "walk" directly.
Of course, we both think that almost all readers are familiar with chicken soup.
However, an undergraduate looking to write a B.S. thesis might read the branching random-walk article without familiarity with branching processes or random walks, and benefit from the hyphen. Please read the article in the state I found it, and tell me whether I was right to be concerned about the needs of civilians.  Kiefer.Wolfowitz  (Discussion) 00:25, 23 April 2011 (UTC) (There was an EC that prevented my direct answer before, 01:40, 23 April 2011 (UTC))

For MF, search among the primary writers of featured articles on English WP. Malleus Fatuorum and I discussed hyphens previously, with good humor, also. See the MOS, also.  Kiefer.Wolfowitz  (Discussion) 23:42, 22 April 2011 (UTC)

Maybe George Bush has corrected others' pronunciation of "nuclear" the way you Trovatore offers advice on hyphens? The MOS states that hyphens are used to prevent ambiguity. Please see Dummett's book for clear and firm advice.  Kiefer.Wolfowitz  (Discussion) 00:10, 23 April 2011 (UTC)
"Branching", like "halting", could modify "walk" directly.  Kiefer.Wolfowitz  (Discussion) 00:10, 23 April 2011 (UTC)
I suppose, in an utter vacuum. No one's going to hear it that way, though. I think this hyphen is completely ill-advised. I'm going to revert your bold move and you can raise an RM if you like. --Trovatore (talk) 00:13, 23 April 2011 (UTC)
Your last sentences don't make much sense, and argue further that you should not be dispensing prose advice, at least not at this hour. Look at the state of the article before I copy-edited it.  Kiefer.Wolfowitz  (Discussion) 00:17, 23 April 2011 (UTC)
Please contribute to the article, before edit warring.  Kiefer.Wolfowitz  (Discussion) 00:21, 23 April 2011 (UTC)
What edit warring? WP:BRD. --Trovatore (talk) 00:26, 23 April 2011 (UTC)
Look, Trovatore. You have been insulting. Do you know anything about stochastic processes? Hardy certainly does, but the article's state was far below his usual standard. I fixed the prose, and provided links to the related areas. You have contributed nothing to the article. Let Hardy revert the move if he wants, when he next edits. I certainly will respect his judgement.
Did you check Dummett's advice. Have you, apparently a logician, heard of him?  Kiefer.Wolfowitz  (Discussion) 00:32, 23 April 2011 (UTC)
I have been insulting? That's pretty rich. I leave it to fair-minded observers to look at the exchange and see who has been more insulting and first. Maybe you got upset because I asked if you were a native speaker? It was a fair question, I think.
Sure, I've heard of Dummett. I don't necessarily agree with him on foundational philosophy, but I got a lot out of Cantorian Set Theory and Limitation of Size. I have never seen a style manual by him and would not take him as an authority on that. --Trovatore (talk) 00:52, 23 April 2011 (UTC)
I dislike Dummett's prose style, but I find his comments thoughtful. Dummett favors clarity and hence suggests hyphens to avoid ambiguity and to save the reader's time.  Kiefer.Wolfowitz  (Discussion) 01:46, 23 April 2011 (UTC)
Sławek is absolutely dead on. Your hyphenation is utterly tin-eared. Get consensus first. --Trovatore (talk) 00:31, 23 April 2011 (UTC)
Who are you to question my English or to take that tone with me? I rewrote the article, repaying a small part of the kindnesses that Michael Hardy has shown me on hundreds of occasions. Write some content, as way to atone for your sins.  Kiefer.Wolfowitz  (Discussion) 00:53, 23 April 2011 (UTC)
I stand by my characterization. --Trovatore (talk) 00:54, 23 April 2011 (UTC)
LOL  Kiefer.Wolfowitz  (Discussion) 01:24, 23 April 2011 (UTC)
Please fix the damage you did to my signatures. Thanks,  Kiefer.Wolfowitz  (Discussion) 01:32, 23 April 2011 (UTC)
Done. Editing mistake; somehow I got the text in two places. --Trovatore (talk) 01:35, 23 April 2011 (UTC)
Thanks!  Kiefer.Wolfowitz  (Discussion) 01:41, 23 April 2011 (UTC)
Please, no hyphen, it is awful. (talk) 18:25, 23 April 2011 (UTC)
Without commenting on the other aspects of this discussion, I agree: the hyphen needs to go. CRGreathouse (t | c) 20:17, 23 April 2011 (UTC)
To comment a little further, I think older works in British English use hyphens more than contemporary or American works do. I can get the impression that Malleus Fatuorum is influenced more by dated British usage than a lot of the rest of us are, which would explain his take on this. To me (US English speaker) the hyphens come across as dated and maybe stilted. I remember an elderly physics professor from a Commonwealth country who wrote "wave-guide" and pronounced it with equal stress on both words, which came across to me as marked. Anyone I know would have written "waveguide" or "wave guide" and stressed "wave" when speaking. Perhaps this should be left up to Michael Hardy per WP:RETAIN. (talk) 00:53, 24 April 2011 (UTC)
You may have misunderstood Malleus: He wanted consistency, and we had a polite discussion of hyphens. Malleus is an excellent writer---unlike the fellow who totally stood behind his synaesthetic complaint that my hyphenation was tin-eared ....
Ditto with David, who thought my hyphenation to be old-fashioned, at least with "real vector-space". :-)
I'm glad somebody agrees that we should let Michael decide, respecting his contributions.  Kiefer.Wolfowitz  (Discussion) 20:51, 24 April 2011 (UTC)
I'm a fan of hyphens, where they go. For example, it wouldn't break my heart if we got rid of the rule that you don't hyphenate "adverb-adjective noun" when the adverb is a regularly-formed "-ly" adverb (and this one is explicitly stated in the MoS).
But only very rarely is it justified to hyphenate on the right, because that's the way modifiers associate naturally. --Trovatore (talk) 08:21, 24 April 2011 (UTC)

Hadamard's lemma

Regarding the article on Hadamard's lemma. It is presented as a first order application of Taylor's theorem; which is fine. But then it assumes that the function is real valued. I'm sure that it works for functions from C to C. Moreover, I'm sure that the statement can be generalised in terms of other fields. Does the statement holds for functions from a field K to a field K? If not, then what are the necessary conditions? What is the most general form of the lemma? All we need is for a function from K to K to be continuous, and for its first order derivative to be continuous. I've listen to talks about p-adic differentiation and integration (i.e. where the field K is a finite field with a prime number of elements); surely the article can be extended. What do we think? Fly by Night (talk) 21:40, 22 April 2011 (UTC)

Over the complex numbers, the result is a trivial consequence of analyticity. I don't know about other fields. In order to define smoothness, some valuation is presumably needed. But (as far as I know) in the general setting of ultrametric fields, the theory of integration is either unsatisfactory or not really connected with the notion of differentiation, so the proof given in the article probably fails in that case. But, as I know very little about ultrametric analysis, it could be that the theorem remains true even in that case. However, that's far from obvious to me and would need a reference. Sławomir Biały (talk) 20:41, 23 April 2011 (UTC)
The article's proof doesn't carry over. Consider f(x) = xp over a field of positive characteristic p. One of the first steps of the proof is to differentiate the given function, and when we differentiate f, the result vanishes. The proof then relies on the integral of the derivative being the original function up to a constant, but this is not true. I'm guessing that one could replace the f(a) term in the statement of the theorem with a function whose derivative is identically zero, and while I'm not an expert the result looks plausible to me. It could also be that there's a different proof that gives a stronger result, perhaps even the same result as over a field of characteristic zero. But again, I'm out of my depth here. Ozob (talk) 01:37, 24 April 2011 (UTC)
True, but theorems have more than one proof. Just because a certain proof fails to adapt to a given setting doesn't mean there is no other proof. As I said, and Sławomir implied, the result is a specific case of Taylor's theorem. We just need to understand what C1(K,K) means for different fields K. It's obvious over R and C (maybe over H too), and I feel that it may be meaningful over Qp where p is prime. Like I said, I have heard people talk about p-adic calculus. For example, the first hit on Google was this: p-Adic Calculus and its Applications to Fractal Analysis and Medical Science Fly by Night (talk) 01:45, 24 April 2011 (UTC)
The statement of the Hadamard lemma isn't quite a special case of Taylor's theorem. Nothing in Taylor's theorem (for several variables) guarantees that the remainder terms will be smooth near the expansion point, and I think that's the subtle point of the Hadamard lemma. In fact, the Taylor remainder terms are non-unique, and we can always make them nonsmooth by subtracting some nonsmooth quantity from one and adding a balancing nonsmooth quantity to another (e.g., ). I agree that it is a consequence of one of the most common proofs of Taylor's theorem, with the explicit integral form of the remainder, but this proof fails in the ultrametric case. If there is a way to get it from Taylor's theorem directly, then that would probably go a long way to establishing it in that case. Sławomir Biały (talk) 02:11, 24 April 2011 (UTC)
Does anyone have any ideas as to how to overcome these obstacles? Fly by Night (talk) 22:21, 26 April 2011 (UTC)

Quasisymmetric map

In the article titled quasisymmetric map, this is given as the definition:

Let (XdX) and (YdY) be two metric spaces. A homeomorphism f:X → Y is said to be η-quasisymmetric or if there is an increasing function η : [0, ∞) → [0, ∞) such that for any triple xyz of distinct points in X, we have

What does mean? Does it mean ? Clearly the article needs work. Michael Hardy (talk) 15:11, 26 April 2011 (UTC)

I am pretty sure that is what's meant, though I'm no expert. I've changed the article accordingly. Ozob (talk) 23:11, 26 April 2011 (UTC)

Template:Cubes proposed for deletion

The Template:Cubes has been proposed for deletion: {{cubes}} Please see the discussion regarding its deletion.

Also, consider expanding and improving the Cubes navbox, which was recently created and newly expanded: In particular, crystallography may have many cubic articles. (It was never meant for mathematicians, who are served by the fine navboxes on polytopes, etc., but for civilians.)

Thanks!  Kiefer.Wolfowitz  (Discussion) 17:14, 22 April 2011 (UTC)

A confession: The former line of "ominous cubes" having the Klee-Minty cube, the Hellraiser cube, and the Cosmic cube was asking for deletion.  Kiefer.Wolfowitz  (Discussion) 17:20, 22 April 2011 (UTC)
The navbox has been deleted. (An archival copy is on my talk page).  Kiefer.Wolfowitz 22:43, 27 April 2011 (UTC)

Shapley–Folkman lemma Review for A-Class

The article Shapley–Folkman lemma has been nominated for A-class review. Your comments are most welcome. Best regards,  Kiefer.Wolfowitz 22:58, 27 April 2011 (UTC)

Math contests medalists (was Peter Scholze at AfD)

The article Peter Scholze is at AfD: Wikipedia:Articles for deletion/Peter Scholze. What do we think of this? (Initially I had missed that he was a Clay fellow, but this could tip the discussion the other way.) Sławomir Biały (talk) 13:14, 28 April 2011 (UTC)

Another IMO related AfD discussion is here: Wikipedia:Articles for deletion/Iurie Boreico. This one seems more clear-cut. Sławomir Biały (talk) 19:46, 28 April 2011 (UTC)

There's also Gabriel D. Carroll and Reid W. Barton to consider. I see that Barton is notable for other stuff as well, and survived an AfD. Tijfo098 (talk) 03:28, 29 April 2011 (UTC)

David Rees (mathematician)

Can someone knowledgeable in commutative algebra add the details about Rees' contribution form some math source (and not a newspaper obit of someone else)? I've added the semigroup theory stuff I knew of. Tijfo098 (talk) 02:01, 29 April 2011 (UTC)

Also the page of his (former) student Michael P. Drazin could enjoy more than a sentence. Tijfo098 (talk) 02:05, 29 April 2011 (UTC)

90-degree rotation in the complex plane

New article looks like it was done as an extra credit project. Well done for what it is but not really encyclopedic in style. Copy to WikiBooks?--RDBury (talk) 04:12, 29 April 2011 (UTC)

Certainly the textbook style is more appropriate to WikiBooks. I have prodded it. Gandalf61 (talk) 08:28, 29 April 2011 (UTC)

multiplicative calculus

Does anyone have some details on Volterra's role in developing multiplicative calculus and to what extent this was influential? The impact of this subject seems to be not much greater than non-Newtonian calculus (see deletion page). Unless we can justify it as a historical page, it may be next. Tkuvho (talk) 04:58, 24 April 2011 (UTC)

My impression is that some people actually study this. But that could be because I've come to associate the moniker of "multiplicative calculus" with things like the product integral. I've not made any systematic effort to locate sources for this article that are independent of the (clearly WP:UNDUE) Grossman and Katz book, and the few other questionable sources listed there. It could go either way for me. Sławomir Biały (talk) 13:55, 29 April 2011 (UTC)

Monty Hall problem

Since the arbitration committee ruling, Monty Hall problem has become a much more cooperative place. Alas, it has also become a place where there are very few editors. If you walked away from the article because of the battleground it became, you might want to consider revisiting it. Guy Macon (talk) 12:52, 25 April 2011 (UTC)

Should it be added to the list of common misconceptions? Tkuvho (talk) 14:00, 26 April 2011 (UTC)
That's a really good question. My first guess is no, based upon what I perceive (but cannot prove) as a failure to meet the "common" criteria. I would guess that most people have not heard of the Monty Hall problem. Totally subjective opinion, of course. Guy Macon (talk)
If the Parade magazine got 10 thousand protest letters, it is safe to assume that a much larger figure are aware of the problem, making it "common". Tkuvho (talk) 04:38, 27 April 2011 (UTC)
Agreed. CRGreathouse (t | c) 16:24, 27 April 2011 (UTC)
Thanks. If we can have just one more editor interested I would take it up at the "list". A few editors there are (rightly) making sure there are no irrelevant additions, and it would be helpful to have the support of the project. The "list" carries heavy traffic (tens of thousands of hits per day sometimes), and gives nice exposure to an elegant math problem (hope I am not offending anyone at WP:probability). Tkuvho (talk) 08:59, 28 April 2011 (UTC)
I support in principle , but the current article has POV tag on top due to years' long disagreement between the regulars as to which solution is wrong. More appropriately add it to WP:LAME for now. Tijfo098 (talk) 06:18, 29 April 2011 (UTC)
I have added a non-controversial entry on Monty at list of common misconceptions that both sides should agree on, see there. Tkuvho (talk) 11:36, 29 April 2011 (UTC)
The delete elite troops are at work already at list of common misconceptions. Tkuvho (talk) 13:34, 29 April 2011 (UTC)

────────────────────────────────────────────────────────────────────────────────────────────────────To Tkuvho: Rather than put the Monty Hall problem specifically into the list of misconceptions, you should figure out what general misconception about probability or statistics is responsible for the popular misunderstanding of MH and put that into the list. Then MH could be linked to as an example. That would make the entry much more useful and important. JRSpriggs (talk) 13:49, 29 April 2011 (UTC)

There is no way of sourcing such "generalisations", and they will certainly be rejected by the troopers. Actually, I disagree with the philosophical thrust of your remarks: the best way of explaining a misconception is by an example, not by discussion of general misconceptions that one thinks people have. At any rate, the recent reverts are by an editor who... has a misconception about Monty Hall Problem! See talk there. Tkuvho (talk) 13:52, 29 April 2011 (UTC)

Category:Non-Newtonian calculus

Do we need Category:Non-Newtonian calculus ? Tkuvho (talk) 08:14, 29 April 2011 (UTC)

No, I don't think so. Neither do we need List of derivatives and integrals in alternative calculi. Ozob (talk) 10:20, 29 April 2011 (UTC)
I think I complained originally about that article looking like it was generated by a program rather than summarizing any source. I see the creator was banned so perhaps a simple prod will get rid of it now. Dmcq (talk) 12:05, 29 April 2011 (UTC)
Whatever material is appropriate for Product integral should be moved there. Tkuvho (talk) 12:12, 29 April 2011 (UTC)
It's hard to see what possible reference use such a table could serve. The sources are a bit dodgy, and do not seem to support the contents of the table. A prod on OR grounds might prove uncontroversial enough. I agree with Tkuvho that some material should probably first be merged to product integral, since that article would benefit from a few choice examples. However it seems silly to attempt any kind of list or table of such integrals, given that the product integral can be obtained easily from the ordinary integral. Sławomir Biały (talk) 13:52, 29 April 2011 (UTC)
I don't know much about product integrals, but with scalar-valued functions you can reduce their evaluation to that of ordinary "sum integrals". My understanding is that the thing that prevents that reduction from making the subject unworthy of further attention is product integrals of matrix-valued functions. With matrix-valued functions you can't just reduce them to sum-integrals that way. But there's nothing about product integrals of matrix-valued functions in the article. If someone is knowledgeable in that area, that material should be added. Michael Hardy (talk) 04:29, 30 April 2011 (UTC)

May 2011


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Top importance, Start class articles

Loosely connected to the recent Signpost Interview, I was thinking about the project's aims etc. Taking the article assessment as a first (rough) indicator for where we are, I was looking at the most important, but worst articles. This is the list ("<500" means that the article is among the 500 most viewed math articles, vital articles are also bold).

  1. Branches of maths / theories: abstract algebra, commutative algebra, group theory, homological algebra, linear algebra (<500), ring theory, differential calculus (<500), functional analysis, mathematical analysis, real analysis, optimization (<500), combinatorics (<500), discrete mathematics (<500), theoretical computer science, foundations of mathematics, pure mathematics, analytic geometry, applied mathematics (<500), mathematical physics, algebraic number theory, analytic number theory, class field theory, algebraic topology, general topology, topology (<500)
  2. (Slightly more) advanced notions: commutative ring, Gaussian elimination (<500), isomorphism (<500), Cauchy's integral formula, differential equation (<500), holomorphic function, limit of a sequence, equation (<500), Markov's principle, sequence (<500), commutative diagram, diophantine equation, expected value (<500), probability (<500), probability distribution (<500), random variable (<500), statistical hypothesis testing (<500), stochastic process (<500), homology theory, open set
  3. Misc/basic notions: 1 (number) (<500), equation solving, formula, subtraction, conjecture (<500), mathematical proof, Fields medal (<500), symmetry in mathematics, percentage (<500)
  4. Biographies: Augustin-Louis Cauchy, Felix Hausdorff, Henri Lebesgue, Jean-Pierre Serre, Karl Weierstrass, Shiing-Shen Chern, Bernhard Riemann

After the Signpost interview the other day, I was curious where WP:MATH will be going etc. Given this list, I'm wondering whether we might want to identify particular target articles etc. For example, I'm personally most concerned/astonished about the group "branches of maths". I did not check each individual article above for its quality, but most are really crappy (or at least short). Another criterion might be "importance to the general public" (i.e., the <500 ones). Most of them are either basic notions or probability/statistics. What do you guys think about all this? I.e., 1) what aims do we have and 2) how do we get there? Jakob.scholbach (talk) 19:31, 24 April 2011 (UTC)

I like to refer to article that get a lot of views as highly visible; you can check page view stats to get an idea of this when the article isn't on the top 500. There are highly visible articles that are low importance and vice versa, but there is a correlation. For about half the articles on the list I have to disagree with the Top importance rating. For example "commutative diagram" may be an important concept, but it's not not something you can build a curriculum on. So perhaps the reason the article is still so short is that it already has most of what there is so say on the subject, or at least what there is to say that wouldn't be better placed in category theory. You're right in that it's a good idea to keep an eye on these articles and work on them periodically. It sets a bad example when a highly visible article is poorly referenced or badly written. Perhaps we could start by picking out one or two of these and making it a goal to bring up them to at least C standard. We used to have a collaboration of the month for that kind of thing, so maybe we can repurpose that.--RDBury (talk) 02:04, 25 April 2011 (UTC)
Optimization should redirect to Mathematical optimization, now called optimization (mathematics).  Kiefer.Wolfowitz 06:23, 25 April 2011 (UTC)
@RDBury: I'm curious what else you consider not top importance. (I agree there is a couple of articles that will be difficult to improve, since their content is not well-delineated.)
Collaboration of the month: how about bringing topology (vital, highly visible) to B or B+ class? (Apparently the list above is slightly out of sync, the article is currently C-class, but clearly deserves attention.) This is a nice topic that might, at least in the long run, showcase both the beauty of mathematics and the performance of WP:MATH. So: who would join this effort (previous collaborations failed because of lack of particpants)? Jakob.scholbach (talk) 14:14, 25 April 2011 (UTC)
To respond to the inquiry: The entries in the Branches of mathematics all seem top importance to me; basically if it could be the title of an undergraduate course then there isn't much doubt that it should be Top priority. Conversely, most of the entries in Advanced/Basic notions I'd change to High rather than Top. Maybe "Probability" should be Top but there seems to be some overlap between that and Probability theory which is also Top. "Limit of a sequence", "Equation Solving", and "Percentage" I'd make Medium. Under biographies I'd at least question all but Cauchy and Riemann. Just my opinion and obviously not one I feel strongly enough about to actually change the ratings and it's not worth the bandwidth to argue about it if someone disagrees.
Topology might make a good article for CotM and it definitely needs work; right now I'd give it a C-. C makes a good standard for "minimum passing" quality, the major aspects of the subject should be covered, references in reasonable shape, understandable enough to make it worthwhile for someone to read it. So to me, getting an article from B to C is not as high a priority as getting an article from Start to C, given the articles have the same visibility/importance.--RDBury (talk) 17:06, 25 April 2011 (UTC)
I agree that the importance of most of the biographies has been overrated. CRGreathouse (t | c) 18:16, 25 April 2011 (UTC)
Regarding the vital articles (bold), a classification new to me: Apparently these 1000 articles have been identified by outsiders while "top importance" articles have been identified within this project. At the moment, Riemann's biography is not vital, merely vital(expanded), and "Equation solving" is not even on that list. On the other hand, the 987 vitals do include 62 "vital" Mathematics articles.
Fully 16 of those are now in Start class. I looked at four of them: Area, Constant, Digit, and Equation. I am not sure whether the latter deserves a Start or a C. It's outlandish that any of the first three is a Start.
Hastily I guess quality classification is so far out of date that its maintenance, rather than improvement of listed articles, may be the only immediately useful application of these lists.
(Btw, it appears that "expansion" of the list of vital articles from about 1000 to 7000 brings only 50% increase in math articles, from 62 to 92.) --P64 (talk) 19:35, 25 April 2011 (UTC)
I have no idea how the "vital" article list was decided, but I think it should be ignored. The list includes combinatorics, game theory, and chaos theory, while leaving out much more important topics like calculus. Weird attention has been devoted to the most elementary notions of geometry as well, listing 15 articles on things like "line", "point", "shape", "conic section". Sure, these are important topics for understanding geometry. But they aren't vital to an encyclopedia. Sławomir Biały (talk) 20:47, 25 April 2011 (UTC)
My understanding is that the vital list is decided by consensus and is limited to 1000 total, of which there are 62 math articles. Because of the limit you can't propose an article be added without specifying which article it will replace. There are similar lists such as Core articles and WP 1.0. WP 1.0 is based on a heuristic formula using article statistics such as page views and number of links, see Wikipedia:Version 1.0 Editorial Team/Article selection.--RDBury (talk) 15:01, 26 April 2011 (UTC)
I'm not suggesting we add anything. I'm saying the whole list is suspect. I mean, is "point" an important concept? Sure, we should have an article about it. But from the point of view of building an encyclopedia, it's not near the top of the list. In fact, in some sense the heuristic isn't even being adhered to: "point", "line", etc., all belong to Geometry, which is probably the only article out of those 15-16 that should be on the list. Sławomir Biały (talk) 15:54, 26 April 2011 (UTC)
I think the idea of having to nominate something to be removed when submitting something is very good. Now if only the government had to do that when it proposed new laws! You could always have a poll about which ones should be included I guess - if so I propose we use Single transferable vote and D'Hondt method to choose them but we probably should have a referendum on the voting method first. :) Dmcq (talk) 17:04, 26 April 2011 (UTC)
As far as I can tell "vital articles" has turned into a forum to discuss why what's important to me is more important than what's important to you. I agree with Sławek that it should be ignored. Any usefulness it ever had is long since past. Ideally it should be marked as "inactive" or some such. --Trovatore (talk) 00:41, 27 April 2011 (UTC)

Articles every Wikipedia should have

I agree with what Sławomir is saying about the vital articles list. But as far as I can tell, the list is not used for anything important. A much more important list is at m:List of articles every Wikipedia should have. This seems to be used by those starting Wikipedias in other languages. The current list is:

  1. Mathematics
  2. Algebra
    1. Group theory
    2. System of linear equations
  3. Arithmetic
  4. Axiom
  5. Mathematical analysis
    1. Differential equation
    2. Numerical analysis
  6. Coordinate system
  7. Equation
  8. Function (mathematics)
  9. Geometry
    1. Circle
      1. Pi
    2. Square
    3. Triangle
  10. Mathematical proof
  11. Number
    1. Complex number
    2. Number theory
  12. Infinity
  13. Set theory
  14. Statistics
  15. Trigonometry

Logic and probability appear not under mathematics but under philosophy. Algorithm appears under computers. This list seems okay considering its size, but I think there are improvements we can make. If it were up to me, I would:

  1. Replace group theory with symmetry. The fundamental idea underlying group theory is symmetry, so an encyclopedia needs an article on the latter before it needs an article on the former.
  2. Replace numerical analysis by calculus. Calculus is fundamental to modern engineering and physics; and as far as I can tell, about half of numerical analysis consists of approximating integrals.
  3. Replace complex number by prime number. Both of these are fundamental concepts, but the basics of complex numbers should already be in the number article, whereas there is a lot to say about primes that does not fit well in that article.
  4. Replace circle and square with angle, area, and Pythagorean theorem. Specific shapes aren't as interesting as concepts; and the Pythagorean theorem, besides being a classic and the only theorem most people have ever heard of, is at the heart of how we measure distance in the real world. (I'm keeping triangle because you can't have an article on the Pythagorean theorem without triangles. The same could be said of squares, but if I include them I have too many articles.)
  5. Remove mathematical analysis and number theory. The list is too short to include fields of math.
  6. Remove axiom. This has a lot of overlap with mathematical proof, truth, and logic (all on the list).
  7. Add logarithm. Not only is this of great historical importance, but logarithms are extremely practical, even for laymen.
  8. Add standard deviation under statistics. Seriously, this is the number 2 most viewed math article on the English Wikipedia (after Einstein, who doesn't really count as math).

Before I propose this change, I'd like some feedback. What would you like to see changed on this list? (Note that the size of the list is fixed; you can't add something without removing something else.) Ozob (talk) 00:34, 27 April 2011 (UTC)

The value of this list: Responses

Basically I think the same as I think about "vital articles". Bluntly, this is a useless exercise, nothing more than an opportunity to argue about what's more important. If you have an article you think is underserved, ask for help on it specifically. --Trovatore (talk) 08:41, 27 April 2011 (UTC)
Ozob, I think the project you are undertaking is too broad in scope. How about focusing on a particular issue? Certainly standard deviation, which does carry heavy traffic, should be on the list if we are to take relevance to the public into account. What would one do about this? Tkuvho (