Wikipedia talk:WikiProject Mathematics

????? Landau

Landau's constants, named after ??????? Landau, are......

etc. My guess is Edmund. Can someone who knows the answer edit the article accordingly? Michael Hardy (talk) 19:19, 7 October 2009 (UTC)

Landau's denesting algorithm

We have no article titled Landau's algorithm. I've added some red links to that article from nested radical and from Susan Landau. If anyone knows anything about it, could they write something? Michael Hardy (talk) 20:20, 7 October 2009 (UTC)

...OK, now I've created the article, but it says nothing specific about the algorithm. Michael Hardy (talk) 20:30, 7 October 2009 (UTC)

Somos sequences

In connection with the deletion nomination for the article on Michael Somos, I started a new article Somos sequence. It's very bare bones right now, just including the basic definitions and a few references, and it's missing a lot of material e.g. on the connections between these sequences and theta-series of elliptic curves. If anyone else wants to take some time to improve it, I'd appreciate it. —David Eppstein (talk) 23:31, 7 October 2009 (UTC)

Synergetics coordinates

Can someone take a look at Synergetics coordinates? I'm not much sure what they are, but the page gets changed from time to time. They seem to be related or unrelated to Synergetics (Fuller), and/or a Clifford J. Nelson, and the latest edits are by a User:Cjnelson9. Shreevatsa (talk) 04:20, 9 October 2009 (UTC)

It all sounds a bit like Sacred geometry to me, I'm not sure an approach as mathematics would satisfy adherents who came along to read about it. Dmcq (talk) 15:26, 9 October 2009 (UTC)

Is there any reason not to prod the article? This article seems to flout just about every policy: WP:OR, WP:COI, WP:FORK, and so forth. 74.98.46.147 (talk) 22:28, 10 October 2009 (UTC)

Robin Thomas

There are currently eight links from articles to Robin Thomas (mathematician), so if somebody knows something, could they put something there? Michael Hardy (talk) 04:48, 9 October 2009 (UTC)

Ascending power numbers on AFD

This section was previously titled: "an article which seems to be maintained by a narcissist who writes for his/her fellow mathematicians"

There's an interesting rationale at Wikipedia:Articles for deletion/Ascending power numbers. Uncle G (talk) 07:32, 9 October 2009 (UTC)

"Michael Somos" nominated for deletion

Comment at Wikipedia:Articles for deletion/Michael Somos. Do not simply say Keep or Delete (or Merge into... or whatever); rather, give your arguments. Currently Somos sequence and Somos' quadratic recurrence constant are mentioned at Michael Somos. Are those enough for "notability"? Are there other things that should be mentioned? Michael Hardy (talk) 19:18, 9 October 2009 (UTC)

Somos' quadratic recurrence constant expresses the constant as the derivative of another constant, a particular value of a three-parameter function. Presumably this should be some derivative of the function itself; can someone fix this? Septentrionalis PMAnderson 01:31, 10 October 2009 (UTC)

Cyclic permutation of integer nominated for deletion

If interested, please comment at Wikipedia:Articles for deletion/Cyclic permutation of integer. Note that just saying delete or keep is not constructive — reasons need to be given. — Arthur Rubin (talk) 00:52, 10 October 2009 (UTC)

Division by two

I just came across the article Division by two, which is unfortunately completely unsourced, and has been so since its creation in 2002. First I thought that this is just an unnotable simple special case, but then it occurred to me that there might be some historical interest in this algorithm (cf. Peasant multiplication which incidentally requires a division-by-two algorithm); does anyone know any sources or background? — Miym (talk) 17:51, 10 October 2009 (UTC)

I added some sources. —David Eppstein (talk) 02:56, 11 October 2009 (UTC)

Looks a lot better but the heart of the article, the algorithm to divide by 2 base 10, is still unreferenced. Factually it looks ok, and most people learned it grade school, so maybe it doesn't need a reference. But I'm not sure it's encyclopedic and WP:NOTHOWTO seems to imply that it isn't. Maybe that section should be moved to WikiBooks.--RDBury (talk) 14:52, 11 October 2009 (UTC)

There's a similar (though not identical) algorithm in the 15th-century algorism citation. And it would be stupid to use WP:NOTHOWTO to imply that descriptions of algorithms are forbidden. —David Eppstein (talk) 16:14, 11 October 2009 (UTC)

Clarity

Now we have

• List of topics in mathematics, and
• Lists of mathematics topics.

Two quite different things.

Great.

All perfectly clear to the newbie or casual reader.

Right?

Michael Hardy (talk) 06:11, 11 October 2009 (UTC)

One is a list and one is a list of lists. It seems to me that the list of lists (whichever it is) should be changed to a category, e.g. [[Category:Lists of mathematical articles]].--RDBury (talk) 14:30, 11 October 2009 (UTC)

Actually, that category already exists Category:Mathematics-related lists, maybe a merge is in order?--RDBury (talk) 14:33, 11 October 2009 (UTC)

Maybe one of them should be called an "Outline." --Robin (talk) 14:41, 11 October 2009 (UTC)

Interesting.

• Lists of mathematics topics is pretty good. But I think we should limit it to listing lists, not lists and categories.
• List of topics in mathematics is not so good. On one hand, it is very incomplete; on the other hand, making it complete would make it pretty much useless.

I would suggest just redirecting List of topics in mathematics to Lists of mathematics topics, and focusing on making the latter as useful as possible. — Carl (CBM · talk) 18:12, 11 October 2009 (UTC)

I'm inclined to agree. Michael Hardy (talk) 21:41, 11 October 2009 (UTC)

The proposal to change lists of mathematics topics to a category is lunacy! This was once a "featured" list, representing Wikipedia's best work. It lost that status only because of a lack of references. Categories are vastly inferior to lists. This list is a good example of HOW categories are inferior to lists. Doesn't Wikipedia have a policy that these two formats are complementary—that one should not eschew one of them because the other exists? Michael Hardy (talk) 21:40, 11 October 2009 (UTC)

Yes, they complement each other and there is a page about it: Wikipedia:Categories, lists, and navigation templates. I agree that Lists of mathematics topics should not be replaced by a category, which would be much worse for browsing. But I think that, within the list of lists, we should not list categories as well. If the lists are set up right, each category that we link to there has a corresponding list that we can link to instead. — Carl (CBM · talk) 22:17, 11 October 2009 (UTC)

Earliest uses of mathematical terms

This is a useful source of external links. But when an anonymous user adds a good link to one of its pages to an article, User:XLinkBot automatically deletes it without any human supervision. If the user also adds content to the article, all such content is deleted along with the link. I think this WikiProject should endorse this particular site. Michael Hardy (talk) 21:51, 11 October 2009 (UTC)

I also find that site useful; I have used it to explain things to my classes. I think that people should feel free to use it in articles. But if it is a reference, the opinions in it should be cited to Miller. So rather than "The first use of 'field' for the algebraic structure was by E.H. Moore in 1893", say "According to Miller (CITE), the first use of 'field' for the algebraic structure was by E.H. Moore in 1893." Questions about priority of results and terminology are notoriously prone to disagreement.

As for XLinkBot, it claims that it allows established users to add links, only reverting new users and IP editors. — Carl (CBM · talk) 22:22, 11 October 2009 (UTC)

Can some domains be white listed? It would make sense to do that. Le Docteur (talk) 00:24, 12 October 2009 (UTC)

I tried something, it didn't work. I will see if it can be done. — Carl (CBM · talk) 02:38, 12 October 2009 (UTC)

Revised Near sets article

Hi all, I have updated the article Near sets based on some feedback I received from this page a few months back. I invite any who are interested to check out the updated article to offer some suggestions to help improve it further. Thanks in advance. NearSetAccount (talk) 15:37, 13 October 2009 (UTC)

Not my cup of tea but it's been nicely laid out. I can think of a lot of articles that could do with a makeover like that. Dmcq (talk) 16:31, 13 October 2009 (UTC)

Leadership?

A bit off-topic -- but -- virtually all of the edits I do at WP are on math articles, with some spill-over to physics and comp-sci. I've not been active for the last few years, because I got tired of the editorial nonsense that goes on. Despite being inactive, I recently was attacked, more or less unprovoked, by a new-age editor who had vandalized an obscure math article I wrote, and someone else reverted. When I told him off, I was promptly piled-on by five admins who blocked me for several weeks. I'm kind of shocked that the power structure here has changed so much that we've got these kinds of nasty, abusive people in admin roles. I complained to the Arb, but they ignored the case. I don't know what to do, other than to complain here, and ask everyone to try to band together, and to figure out how to get the ugly admins and the (incompetent?) leadership out of power, redo Wikipedia leadership, and restore some sanity. linas (talk) 16:42, 13 October 2009 (UTC)

The following is apparently what happened. In the article titled history monoid, this work was cited:

• G. Rozenberg and A. Salomaa, editors, Handbook of Formal Languages, Vol. 3, Beyond Words, pages 457–534. Springer-Verlag, Berlin, 1997

User:Aboutmovies mistakenly thought that "Beyond Words" was the publisher rather than part of the title, and changed it to [[Beyond Words Publishing|Beyond Words]], so that the reader saw this like: Beyond Words. Someone changed it back with an explanation in the edit summary that that's part of the title, not the name of the publisher. The publisher is Springer-Verlag. Michael Hardy (talk) 18:35, 13 October 2009 (UTC)

The contribution of Linas is quite impressive (I have visited several pages on different topics). However, his message above contains no links, and so, I do not understand what is really the problem. Boris Tsirelson (talk) 19:18, 13 October 2009 (UTC)

There is an ANI discussion here with opinions by various people and additional pointers. Hans Adler 19:21, 13 October 2009 (UTC)

This has been forum-shopped to Mediation, to the Arbitration Committee, and now to the talk pages of several WikiProjects. Editors coming to this situation with no prior knowledge should read Wikipedia:Administrators' noticeboard/IncidentArchive564#Nuclear meltdown at User talk:Linas, Wikipedia:Administrators' noticeboard/IncidentArchive567#User:Linas again, Wikipedia:Requests for mediation/User:Linas, and this declined ArbCom request to get up to speed. Please place all further discussion at Wikipedia:Administrators' noticeboard/Incidents#Linas, soapboxing on wikiprojects (and userpage), rather than having lots of little disjoint discussions everywhere that this has been shopped around to. Uncle G (talk) 02:05, 14 October 2009 (UTC)

Comments. Linas, you have been a good if quirky contributor to the project. Not so much has changed, but there is a definite effort on foot to improve standards of civility around the site. Just as in the past we have discussed mathematics and you have accepted that you have made technical mistakes, I think you should accept that you have made a mistake of escalation over the initial issue, which need not have been a big deal. If you need an advocate for your past efforts, I'll speak to whoever needs to hear about that. But when I have seen others attack the "system" in this way, I have always felt they were misunderstanding some of the factors, even if the mistakes were not all on one side. Charles Matthews (talk) 08:09, 14 October 2009 (UTC)

Does anyone else get a nagging feeling that there are two (or more) people running the User:Linas account? It is difficult to reconcile the impressive list of contributions with the spoiled teenager that calls people "fuck brained idiots". Is that the normal Jekyll and Hydeism from this account? Or is a checkuser perhaps in order? Wknight94 ^talk 10:55, 14 October 2009 (UTC)

Calling Linas a "spoiled teenager" is not really helpful. Linas, though prickly at times, has made major contributions to our project, and while he has not handled this situation very well, it would be good for others to examine their behavior as well. Paul August ☎ 13:09, 14 October 2009 (UTC)

My point was that it seemed like a spoiled teenager personality. I've never known anyone over the age of 17 to use such terms. If it turned this was a mathematics post-grad sharing an account with an angry 15-year-old brother, I would not be surprised in the least (and it wouldn't be the first time I encountered such a situation). Wknight94 ^talk 13:31, 14 October 2009 (UTC)

I understand the point you are trying to make. Nevertheless I don't think the way you are trying to make it is helpful. Try to consider how you would feel If someone said your behavior seemed like that of a "spoiled teenager". Paul August ☎ 13:54, 14 October 2009 (UTC)

I would feel like maybe I am coming across quite immaturely and I should probably smarten up (as we Maine folks say). But if you think I'm an anomaly in that regard, that's fine, I'll drop it. Wknight94 ^talk 14:11, 14 October 2009 (UTC)

Thanks. Paul August ☎ 17:55, 14 October 2009 (UTC)

I don't think so. From the contribs, it seems like Linas has a good understanding of advanced math topics. Consequently, people who don't understand advanced math appear stupid to Linas, and by extension, they appear to be "fuck brained idiots." --Robin (talk) 11:54, 14 October 2009 (UTC)

I am not seeing anything that can't be explained with misunderstandings. If I had been in Linas' situation and had believed that Aboutmovies was a sneaky vandal, I might not have behaved too differently. Hans Adler 12:11, 14 October 2009 (UTC)

I knew two people, incidentally, one being a University Math Professor, who could go berserk at any manifestation of stupidity however minor. And do not forget we do not know anything about linas' personal life, the trigger might have been outside Wikipedia. (Igny (talk) 12:45, 14 October 2009 (UTC))

Charles and others, it would seem to me that on this point, the goals of increasing civility on Wikipedia and actually building a good encyclopedia are somewhat in conflict. Wikipedia is not so rich that it can afford to run off everybody who's capable of being provoked, no matter how great their energy or extensive their contributions. Frankly, the whole incident looks like it could've been avoided if people had been allowed, you know, to blow off steam. Standards of admin action developed amidst our most ferocious disputes and hardened by arbcom remedies on bitter cases of protracted conflict do not need to be applied injudiciously across the rest of Wikipedia. Ray^Talk 15:30, 14 October 2009 (UTC)

No, the goals of increasing civility and, for example, increasing our participation of women are entirely in line with each other. As for any other group, such as older folk, who find displays of petulance and profanity to be a discouragement. I think you'll find that I was suggesting a way ahead, rather than arguing that the business was handled the best way. Charles Matthews (talk) 16:32, 14 October 2009 (UTC)

(edit conflict) @Ray: At the risk of getting into a general civility discussion, your argument cuts both ways. Wikipedia is not so rich that it can afford to have calm civil productive editors run off by people who overreact and blow innocent mistakes completely out of proportion. People won't accept that type of incivility when they're being paid, much less when they are volunteering. Wknight94 ^talk 17:27, 14 October 2009 (UTC)

Wknight, you are correct. This is why this is a situation where I felt a touch of forbearance and discretion, rather than a rules change, would've been a good idea. It was a situation where an editor was blowing off steam on somebody else's talk page, and the person to whom he was blowing off steam was not the one being insulted. That was not a situation threatening to escalate absent outside intervention, and in hindsight it clearly was a situation where outside administrator intervention was likely to aggravate things, and I believe it did not require hindsight to forsee it as such. Charles, sorry for misunderstanding your comments above. Ray^Talk 19:35, 14 October 2009 (UTC)

People! Please! This has nothing to do with mathematics articles. Please take it to the WP:AN/I section linked-to above. Uncle G (talk) 23:56, 14 October 2009 (UTC)

• No, I think a discussion here has been fruitful, and has reached some people unaware of the civility issue, in the terms in which it is now posed. And I for one am not that impressed with AN/I as a forum for actually resolving disputes, rather than propelling rather reactive admins in the direction of trouble. It has no charter, you know; it is not appointed in any way, and is simple a "noticeboard", i.e. a sort of process that is unregulated. Which is part of the problem here, possibly. In any case it has no particular jurisdiction and there is no need to make claims for its centralising function that cannot be upheld. Charles Matthews (talk) 09:45, 15 October 2009 (UTC)
  • None of which is relevant, and framing this as some sort of bizarre antipathy to WP:AN/I is ludicrous (especially given that the "centralizing function" in this case not only can be upheld, but is downright obvious). This discussion has nothing to do with mathematics articles, isn't a dispute resolution, and is a ForestFire that has been deliberately ignited in multiple places by Linas. Note that the people at Wikipedia talk:WikiProject Physics have seen the sense of having this discussion in one place, and that their WikiProject is not the proper forum for it. They at least would like the attempts to stir up drama irrelevant to their project off their project, so that they can stick to what they actually set up the project for. ☺ Uncle G (talk) 11:23, 15 October 2009 (UTC)

With all due respect, the members of the project can discuss what they like here; and the status of a long-term, valued contributor to the project is hardly off-topic. It is relevant to getting articles written in a specialist area, where there is a shortage of specialists, if that has to be spelled out for anybody. I've made it clear above that I have interacted in the past with Linas. So that would be enough heckling, really. Charles Matthews (talk) 11:33, 15 October 2009 (UTC)

Agree with Charles Matthews. Here we can have an informed, civilised and on-topic discussion. At ANI that is .. well ... less likely. Gandalf61 (talk) 11:39, 15 October 2009 (UTC)

Yes, Charles has it right, this conversation is certainly relevant to this project. Paul August ☎ 14:57, 15 October 2009 (UTC)

Indeed, a point that I made on linas' talk page is that it would be better to decentralize this sort of thing by strengthening the role of Wikiprojects in dispute resolution. This can probably help to mitigate some of the drama that ordinarily goes with WP:ANI. Le Docteur (talk) 01:44, 16 October 2009 (UTC)

The difficulty, as with all aspects of life, is finding people who are interested. At least people who follow ANI are trying to follow the drama; people who follow wikiproject talk pages may not be interested in dispute resolution. More to the point, they may feel that they just don't want to get involved in in the interpersonal disputes of the other editors in their project. I know that I often feel that way. — Carl (CBM · talk) 02:02, 16 October 2009 (UTC)

This is too bad, Carl. As good citizens, we should certainly take interest in the places where we live and work and strive to maintain their integrity. It is all too easy to write off disputes and even abusive behavior as "drama" and "interpersonal relations" and to say "count me out". Worse, there is a sliver of editors, including some even here, on the math project, who take advantage of the apathy you've described and engage in egregious violations of even the most basic wikipedia policies with complete immunity. Leaving it to ANI or to drama-obsessed crowds has not worked in the past and will not work in the future. You, no doubt, know several instances of highly valued and productive contributors to the project who have stopped participating for this very reason. I, for one, became very disillusioned with the lack of commitment on the part of the math community on wikipedia to maintaining supportive atmosphere conductive to creating a quality math encyclopaedia. Arcfrk (talk) 16:11, 16 October 2009 (UTC)

Gyrovectors

I am not sure if this is the right place to ask but could somebody have a look at the Gyrovector space article. Martin Hogbin (talk) 22:26, 13 October 2009 (UTC)

I haven't really examined the article to determine if it is obvious woo or not, but there are only 7 mathscinet links with gyrovector in the title, all of which were published by a single author, although some of these were actually reviewed. It is not cut and dry, but this does seem to be a case in which an encyclopedia article is probably premature. Le Docteur (talk) 00:15, 14 October 2009 (UTC)

These Google books and Google Scholar results show that there are far more than 7 papers or one author.

Some of those results aren't relevant, but most of them are.

Charvest (talk) 03:37, 14 October 2009 (UTC)

Article needs a fair amount of chat removed. There is a nonassociative structure in there to document. Articles in the area of linear algebra in mathematical physics do tend to lead off with claims that this is an entirely new way to look at things; that is almost always going to be POV, and such claims are not what make a topic notable. Charles Matthews (talk) 07:30, 14 October 2009 (UTC)

Halting problem and Likebox

In my opinion, he's at it again. I can't find any restrictions he may be under, but he's reformulating the halting problem to remove the input, claiming it's the "modern" approach; and then adding a "modern proof", replacing the diagonalization by quining. I'm at 3RR, but I believe he is, also. Any input as to whether any of his assertions are correct (whether or not "input" is "modern", the proof uses inputs) would be appreciated. — Arthur Rubin (talk) 01:17, 15 October 2009 (UTC)

First, you aren't at 3RR, and neither am I. You are at "1R", and I am at "2R". If you revert some of the material, I'll discuss.

Second, yes, I'm "at it again", because I was annoyed the first time that people would not accept discussions which sound a little different than textbooks. There are some proposed guidelines which I think help: WP:ESCA, and perhaps with these guidelines, consensus can be made to swing the other way.

I have no complaints with your behavior, and I understand and sympathize with your position. I just disagree.Likebox (talk) 01:21, 15 October 2009 (UTC)

While I agree with both your points, the canonical description of the Halting problem is with input. See the most modern book in Complexity theory (Arora and Barak's 2009 text); even that treats the version with input. While I like the quining and no-input version, that shouldn't be the main version in the article. I believe a separate section should highlight the formulation without inputs with the quining proof. --Robin (talk) 01:44, 15 October 2009 (UTC)

But the same book surely states the theorem with no input too somewhere. That's also a standard result. For example, Wolfram mathworld states it without input.

Also from googling:

As an example of his thought let's look at a proof that there is no way of telling in general once a computer has embarked on a calculation whether that calculation will terminate in an answer. This problem is known as the "Halting Problem for Turing machines" and was first proved in the 1937 paper[2] in which he introduced his machines.

Again, no input. I have found cases where people state it with input, and others where it is stated without. Since both are true, both are almost identical, and the input is only there to simplify the proof a tiny bit, I think it is misleading to make the input so prominent in the lead.Likebox (talk) 01:57, 15 October 2009 (UTC)

As I said, I appreciate your point, and I do like the no-input version, but the article's lead section should have the canonical version which everyone is used to reading in their first year CS course. Moreover, I think the diagonalization proof is easier for a new reader. Once the reader has grasped this, the reader can move on to the no-input version and quining proof. --Robin (talk) 02:04, 15 October 2009 (UTC)

Mm. I am far from knowledgeable about computation, but I just took a look at Sipser (which I understand to be something of a standard introductory text in the subject), and he uses finite input strings in his description. I think, if people knowledgeable on the subject are not in agreement to the contrary, we should probably stick to the standard pedagogical approach. It's fairly common for there to be sections towards the end describing generalizations and extensions of the theory, however, so that might be a good place for Likebox to put his stuff? Ray^Talk 01:38, 15 October 2009 (UTC)

The issue is entirely pedagogical. I agree that textbooks do not often mention quines in this context, but I feel that this is a pedagogical mistake. People knowledgable in the subject don't think about this, because it is too elementary to waste time thinking about. It is in these situations that bad pedagogy can flourish.

But we don't have to be stuck with bad pedagogy. If there is a nice text which explains sourced material well, but doesn't sound exactly like a textbook, that's OK according to WP:ESCA, so long as it is accurate, clear, and explains intermediate steps in well referenced results.

In this case, the theorem is this: You can't write a program HALT which takes P as input and decides if P halts or not.

One way to state the proof is: Write SPITE to print its own code into R, calculate HALT with input R, and if the answer is "R halts" go into an infinite loop, and if the answer is "R doesn't halt" to halt.

This proof is trivial, and the only question is whether a program can be made to write its own code. This is slightly nontrivial, but it is an exercise for computer science freshman.

The other way to prove this is to say "It is undecidable whether program P with input I halts for arbitary P and I". Then you prove it this way. Suppose HALT(P,I) tells you whether P and I halts. Then write SPITE to take input I, and evaluate HALT(I,I), and if the answer is "I halts on input I" SPITE goes into an infinite loop. If the answer is "I does not halt on input I" then SPITE halts.

Then you ask if SPITE is given as input the code for SPITE, what does it do? You see, it's exactly the same proof, except that the code for SPITE is given to SPITE as input, instead of being generated by SPITE at step 1.

I think that the proof where SPITE prints its own code is clearer. To prove that a program can always print its own code is very simple, using the diagonalization argument.Likebox (talk) 01:52, 15 October 2009 (UTC)

I disagree with Likebox's opinion that Wikipedia should promote pedagogical innovations not present in standard textbooks like stating the Halting Problem the way he likes it. Pcap ping 07:41, 17 October 2009 (UTC)

Also Gödel's incompleteness theorems

The same issue at Gödel's incompleteness theorems, where Likebox has previously added "modern" proof that was removed. It helps to have more eyes on these pages. — Carl (CBM · talk) 02:05, 15 October 2009 (UTC)

This is particularly problematic because Likebox tends to revert the removal of his proofs. — Carl (CBM · talk) 02:10, 15 October 2009 (UTC)

I don't like it when people delete 8K of material written over several hours without discussion. It's impolite to the effort I put into the new text. I know you have issues with this stuff, but mull it over. These proofs are sorely needed. I have had discussions about this with five or six mathematics students over the past week, and their encouragement is the only reason I came back to these pages. The current proofs of Godel's theorem is illegible, and it is beyond the grasp of most undergraduates. That needs to change, and WP:ESCA is a good way to allow it to change.Likebox (talk) 02:13, 15 October 2009 (UTC)

The issue was discussed, in depth, more than once. For example, see this discussion in 2007. — Carl (CBM · talk) 02:15, 15 October 2009 (UTC)

Although I agree that the main proof should be the one in the article, I do like Likebox's computer-sciencey proof. Maybe there's some way to have Likebox's proof too, without having it as the main proof in the article? Or perhaps put it in the Proof Sketch article, as an alternative proof sketch? --Robin (talk) 02:18, 15 October 2009 (UTC)

Even if we did want to include Likebox's proof in the article, we would need to rewrite it significantly to fix the terminology to match the literature, and to make the tone encyclopedic rather than pedagogical. Based on past experience, I do not believe Likebox accepts such rewrites. — Carl (CBM · talk) 02:26, 15 October 2009 (UTC)

Right, I agree with you. I have no prior experience with Likebox, so I can't say anything about the problem you mentioned. I have seen a CSish proof of Godel's incompleteness in Scott Aaronson's lecture notes. Perhaps this will help? --Robin (talk) 02:41, 15 October 2009 (UTC)

The proof that Likebox is inserting is actually the same as the proof already there, just rephrased to use words like "program" and "quine" (the latter incorrectly). If we were to rephrase Likebox's proof into standard terminology it would simply be the usual proof via the diagonal lemma. This is the proof presented by mainstream mathematical logic texts. This has been explained to Likebox before. — Carl (CBM · talk) 02:49, 15 October 2009 (UTC)

I see what you're saying. This explains the fact that there aren't a multitude of texts out there with Likebox's proof: because both proofs are essentially equivalent, and after formalizing Likebox's proof, you end up with something similar to the original proof. --Robin (talk) 03:41, 15 October 2009 (UTC)

Note: I have posted about this to [1]. — Carl (CBM · talk) 02:26, 15 October 2009 (UTC)

There is no OR in this proof, it is equivalent to standard proofs, as CBM has said. The issues are with what type of material can be included here.

To Robin: the reason the proof is not presented the way I present it is not because it is harder to formalize. The proof I give is at least as simple to formalize as standard proofs. It's a little easier, in fact, because the formal structure of modern computers is already well understood.

But even though the logic is equivalent, style is very important. The style of proof that I gave, now presented on Godel's incompleteness theorems talk page, is vastly easier for undergraduates and non-specialists to understand. It is also easier for most specialists to understand, especially regarding Rosser's proof (which is a notorious sticking point for students). In my experience, a presentation of the proof in this style takes about 10-20 minutes to fully internalize and understand, while the standard presentations take days or weeks of intensive study to fully understand. Needless to say, learning the easy proof allows students to then understand the standard proof much more quickly. The proof I gave can be understood by any layperson who is somewhat familiar with mathematics.

If you support the material, realize that politics is now slightly against these types of proofs. There are two editors, CBM and Arthur Rubin, who oppose this material. They oppose it mostly by inertia, this is not the first time I have tried to incorporate the material. It requires more editors with a strong opinion for inclusion to get this material into the article.Likebox (talk) 20:40, 15 October 2009 (UTC)

I see no compelling reason not to use the standard proof (not the Likebox version) Verbal chat 16:28, 16 October 2009 (UTC)

After a long discussion with Likebox and CBM, I also feel that we should use the standard proof (the one that appears in text books). --Robin (talk) 17:06, 16 October 2009 (UTC)

gratuitous application of l'Hôpital's rule

I'd be grateful if someone could comment on talk:sinc function. — Emil J. 16:22, 16 October 2009 (UTC)

Preposed removal of /Comments pages

Mathematical article assessments on article talk pages (the {{maths rating}} templates at the top of mathematical article talk pages) are often backed up by comments. These comments provide, at the very least, a signed date for the assessment (which has in the past been regarded as an essential part of our assessments); ideally they also provide basic suggestions for improvement. This project has found such pages useful.

A recent Village pump discussion suggests that editors elsewhere may not be fully aware of the value of /Comments pages to WikiProjects. A greater awareness may result in a better conclusion. Geometry guy 23:08, 16 October 2009 (UTC)

Computability theory, Complexity theory and Formal languages

I'm cross posting this from WikiProject CS since there are many editors here who are interested in these topics. If interested, please take a look at my request on Wikipedia_talk:WikiProject_Computer_science#Can_someone_take_a_look_at_this.3F, and reply there to keep discussions unfragmented. In short, I've translated a German image which shows the relationship between these three fields. It might make a good addition to some of our articles on these topics. Thanks. --Robin (talk) 17:17, 17 October 2009 (UTC)

"Infoboxes" on number articles

List of numbers – Irrational numbers ζ(3) – √2 – √3 – √5 – φ – α – e – π – δ

List of numbers – Irrational numbers γ - ζ(3) – √2 – √3 – √5 – φ – α – e – π – δ
Number System	Evaluation of $\pi$
Binary	11.00100100001111110110…
Decimal
Hexadecimal
Rational approximations	22⁄7, 223⁄71, 355⁄113, ... (listed in order of increasing accuracy)
Continued fraction	[3; 7, 15, 1, 292, 1, 1, 1, 2, 1, 3, 1, 14, 2, 1, 1, … ] (This continued fraction is not periodic. Shown in linear notation)
Trigonometry	$\pi$ radians = 180 degrees

Earlier today I tried to remove the "infobox" (displayed right), from e (mathematical constant), since it doesn't seem to me to add much of use to the article (as well as the fact that the links listed seem a bit arbitrary), I was reverted with the comment "the same template is used in the aticle about pi and all of the other irrational numbers of interest". And in fact the article for each of the constants listed in that infobox contains the infobox, and some have sprouted more expansive infoboxes (e.g. see the infobox for Pi displayed right). What do others think about these? Paul August ☎ 18:13, 17 October 2009 (UTC)

I believe the pi infobox is pretty frivolous for a lot of reasons. First, putting links to list of numbers and irrational number is not informative. Second, linking to other "irrational" numbers is unnecessary. Third, pi's hexadecimal and binary expansions add absolutely no insights into the nature of this number. Neither does the continued fraction expansion (that would make sense for numbers where the continued fraction expansion has a pattern or defines the number). Ditto about the rational approximations.

All in all, while some people may think infoboxes are pretty and summarize some properties, this particular one adds no value I can see. I'd say we should cut it out. Oleg Alexandrov (talk) 22:20, 17 October 2009 (UTC)

I agree. The irrational numbers infobox is silly, and the pi infobox is obnoxious. Both should be removed. Ozob (talk) 00:55, 18 October 2009 (UTC)

It seems to me that these particular infoboxes, even more than infoboxes in general, are just infotainment. I don't mind them very strongly, but I am also inclined towards removing them. Hans Adler 01:09, 18 October 2009 (UTC)