# Wikipedia talk:WikiProject Mathematics

 This is a discussion page for WikiProject Mathematics This page is devoted to discussions of issues relating to mathematics articles on Wikipedia. Related discussion pages include: /Conventions /Graphics /PlanetMath Exchange /Proofs /Typography /Wikipedia 1.0 Mathematics Portal MoS Mathematics Reference desk (mathematics) (Please ask general questions of interest here). Please add new topics at the bottom of the page and sign your posts.

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Hi, could anyone here help fix a few links to disambiguation pages?

Bolza surface has a link to Perturbation, Finsler manifold has a link to Minkowski norm and Simplicially enriched category has a link to Simplicial category.

I don't know whether there is a good target article for the links in question, or whether the link should be removed, as my level of Mathematics is not advanced enough to understand these topics. Thanks for your help. IffyChat -- 12:20, 31 July 2018 (UTC)

"Bolza surface" and "Finsler manifold" now fixed, but "Simplicially enriched category" is not. Boris Tsirelson (talk) 14:27, 31 July 2018 (UTC)
I "fixed" the last one by just removing that section; it was in pretty bad shape – bad English, questionable math, broken refs, etc. –Deacon Vorbis (carbon • videos) 15:29, 31 July 2018 (UTC)

## Vital articles

Is it just me, or are a lot of articles getting promoted to "vital"? I don't normally pay attention to that sort of meta classification, but SSTbot has been promoting lots of articles that I wouldn't have thought should be considered "vital". For example, Bessel function is rated as "mid" importance by WikiProject Mathematics. Should it be only mid importance, but also vital? (Note: I have no strong opinions about any of this. I'm just noting that something doesn't quite jibe about it.) Sławomir Biały (talk) 20:45, 1 August 2018 (UTC)

As far as I know, the SSTbot is promoting articles in Wikipedia:Vital_articles/Level/5/Mathematics; for instance Bessel function is listed at Wikipedia:Vital_articles/Level/5/Mathematics#Calculus_(32_articles). I, too, don't have much of an opinion on what is included, but that is probably the place to discuss. --`{{u|Mark viking}} {Talk}` 20:54, 1 August 2018 (UTC)
Quantum cohomology is a more egregious example than Bessel function (and I'm even a fan of the former). I don't understand the procedure by which Wikipedia:Vital articles/Level/5/Mathematics is populated. Mgnbar (talk) 21:10, 1 August 2018 (UTC)
I would recommend mostly ignoring VA in general. I'm an occasional participant in level-3 discussions, but largely against my better judgment. I don't really see the point of the whole thing. It seems to be mostly a place to argue about why what's important to me is more important than what's important to you. --Trovatore (talk) 21:28, 1 August 2018 (UTC)
Level 5 is a recent expansion to vital articles. Right now it's basically a WP:BOLD wildwest. Once it's got its critical mass of articles, I suspect there'll be an actual process in place. If anything egregious is missing, add it, if something completely silly is added, remove it. Headbomb {t · c · p · b} 23:55, 1 August 2018 (UTC)

Yeah, a bot for tagging these articles ran today. The current "quota" is 1200 articles (total) at level-5, including 300 at level-4 (biographies excluded from that count). My mental threshold is whether the topic would be discussed in a book-length mathematics encyclopedia. That's probably anything at "mid" priority or higher; Bessel function is One of the 500 most frequently viewed mathematics articles. and is probably important enough to be listed (no opinion on Quantum cohomology). power~enwiki (π, ν) 01:53, 2 August 2018 (UTC)

If anything of "mid" importance is "vital", then we have a serious terminology mismatch. (This is not an attack on you, though. :) Mgnbar (talk) 11:43, 2 August 2018 (UTC)
Maybe a better terminology would be "vital indeed" for level 1, "vital" for level 2, "half-vital" for level 3, "not quite vital" for level 4, and "not vital at all" for level 5?   :-)   Boris Tsirelson (talk) 11:16, 3 August 2018 (UTC)
My issue is not with the article Bessel function per se. But many of the other articles being promoted to vital in SSTbot strike me as borderline at best. I realize a case could be made that articles like Methods of detecting exoplanets or Planetary differentiation, for example, are vital articles. But, on the other hand, something doesn't quite jibe about many of the articles I see getting promoted. Many are, for lack of a better word, borderline. Often they are only rated "mid" importance, for example, in their WikiProject designations. Something doesn't feel quite right if a WikiProject designates an article as "Mid" importance, but then a bot apparently upgrades it based on some list somewhere of "vital" articles. Why is there a discrepancy in the assessment? Sławomir Biały (talk) 12:07, 3 August 2018 (UTC)
If you want to suggest a different name ("Moderately vital articles") that isn't quite as silly as that suggestion, please do so. power~enwiki (π, ν) 03:16, 5 August 2018 (UTC)
These all should be clearly more vital than articles such as Maris–McGwire–Sosa pair, Square Root Day, or Hensel's lemma. power~enwiki (π, ν) 03:20, 5 August 2018 (UTC)
One of those things (Hensel's lemma) is not like the others. It actually has some mathematical significance rather than being a piece of cultural trivia. —David Eppstein (talk) 04:02, 5 August 2018 (UTC)
Yes, Hensel's lemma is vital in this apparently non-vital sense, which apparently means "something Wikipedia should have an article on". Sławomir Biały (talk) 12:02, 5 August 2018 (UTC)
I agree there's a (large) gap between "important to have an article, but not the top 1000 topics" and "crap that is too much work to get deleted". power~enwiki (π, ν) 16:16, 5 August 2018 (UTC)
I feel the best approach to vital articles is "If this were an encyclopedia on topic X, and we only have room for Y topics, would this make the cut?" When you have 5 articles to work with, it's pretty reasonable to exclude Calculus. But if you have ~50 articles to work with, then it can make the cut. I don't know if I'd include Bessel functions if I were limited at 300 topics, but certainly I'd talk about them if I had room for 1100 topics. At that level, I'd also leave out Maris–McGwire–Sosa pair, but there's room to talk about Recreational mathematics. Headbomb {t · c · p · b} 16:34, 5 August 2018 (UTC)

## Newton–Cotes formulas mistake?

Hi would someone be able to check the 'Newton–Cotes formulas page; Closed Newton-Cote formulae' section, specifically the (3rd and 4th) rows of formulae in the table...

1) The Simpson's 3/8 rule & Boole's rule do not appear to be consistent with the Trapezoid rule and Simpsons rule in that where they have used (b-a), I feel like they should have used (b-a)/n where n is the degree. This appears to be what they have done for trap/simpsons rule. The linked Boole's rule wiki page itself does have the initial coefficient as 2*h/45 and I believe h := (b-a)/4, meaning that using the style implemented on the Newton Coates page, the first coefficient should be 1/90 (i.e. (2/45)/4), and similarly the 3/8th simpsons rule should start with 1/8. As a reference I'm comparing to the Introduction to Numerical Analysis Springer book by Stoer and Bulirsch who provide a table for comparative purposes.

2) In the book I've just mentioned (page 126 for the table), the names of the interpolation schemes are different too. That reference names the degree 4 scheme as Milne's rule, whereas the wiki page seems to refer to places where it is called Boole's rule, and yet it uses Milne's rule for a different formula further down. I feel like (at least personally) I'm getting confused by all the names. Is there any way to clear it up?

Thanks, — Preceding unsigned comment added by 2a0c:5bc0:40:107c:c479:58f9:bf8b:42cf (talk)

Courtesy link: Newton–Cotes_formulas#Closed_Newton–Cotes_formulas. --JBL (talk) 13:45, 3 August 2018 (UTC)
I changed the coefficients to match, but I'm not going to wade into the naming stuff. –Deacon Vorbis (carbon • videos) 13:56, 3 August 2018 (UTC)

## Help with "Good Article" review of "Georg Cantor's first set theory article".

Here is the article: Georg Cantor's first set theory article

Here is the "Good Article" review page: Talk:Georg_Cantor's_first_set_theory_article/GA2

I created the page originally, but most of what's there now is the work of Robert Gray, a historian of mathematics who has published refereed scholarly articles on this topic.

Work is needed to respond to the recommendations on the review page in order for this article to be promoted. There is Robert Gray is on vacation and not aware of the current situation. Michael Hardy (talk) 15:49, 3 August 2018 (UTC)

I like the article, and I think it would be a shame if the nomination fails simply because some editor is having two weeks off. Michael, maybe you could ask the reviewer to extend the on hold for a bit longer than 7 days (which anyways are a somewhat arbitrary interval in my mind)? Jakob.scholbach (talk) 21:14, 3 August 2018 (UTC)
I still very seriously object to the name. My opinion is that articles about specific publications should be named after the publication — in this case On a Property of the Collection of All Real Algebraic Numbers.
There are several considerations that lead me to this conclusion. The most important one is that descriptions are the last choice for the titles of WP articles. For articles whose title is not a simple common noun, we should strain to use proper names and terms of art before natural-language descriptive phrases.
Secondarily but still importantly, article strikes me as a bad description for this seminal paper. TIME has articles. Wikipedia has articles. Research scientists publish papers. They may also publish articles, but the articles are less important than the papers. The articles tend to be surveys and reviews rather than original contributions. --Trovatore (talk) 21:23, 3 August 2018 (UTC)
I don't remember what this article's title was originally. I can't find it in the edit history, and I wonder if that has to do with some deletions and restorations and edit history mergers. I remember that it was changed to its current title from something else. I think it may have been something like "Cantor's first uncountability proof". Michael Hardy (talk) 17:16, 4 August 2018 (UTC)
ok, I found it. It was Cantor's first uncountability proof. I agree that the title of Cantor's paper would be better than the Wikipedia article's current title. Michael Hardy (talk) 17:19, 4 August 2018 (UTC)
I am inclined to agree with the proposal to make the title of Cantor's paper the title of this article. Here's another instance: An essay towards solving a problem in the doctrine of chances. Michael Hardy (talk) 18:15, 4 August 2018 (UTC)

I've put some comments here on the review page. Opinions? Michael Hardy (talk) 18:34, 4 August 2018 (UTC)

## Wiki Education hiring an experienced Wikipedian

Wiki Education is hiring an experienced Wikipedian for a part-time (20 hours/week) position. The focus of this position is to help new editors (students and other academics) learn to edit Wikipedia. The main focus of the position is monitoring and tracking contributions by Wiki Education program participants, answering questions, and providing feedback. We're looking for a friendly, helpful editor who like to focus on article content, but also with a deep knowledge of policies and guidelines and the ability to explain them in simple, concise ways to new editors. They will be the third member of a team of expert Wikipedians, joining Ian (Wiki Ed) and Shalor (Wiki Ed). This is a part-time, U.S. based, remote or San Francisco based position.

We are especially interested in people with a background editing maths-related articles. See our Careers page for more information. Ian (Wiki Ed) (talk) 20:07, 6 August 2018 (UTC)

## Draft:Paraconsistent mathematics needs help

The creator, Schiszm seems to be a competent academic writer and my gut says this surely should be a notable subject, but the draft needs to be substantially reworked to fit in WP, particularly in terms of the style and tone. Please advise and assist the original contributor. Thanks Roger (Dodger67) (talk) 18:20, 9 August 2018 (UTC)

## HTML entities and Unicode characters

FYI, I'm proposing a stronger style convention for special characters which are often seen in math-related articles. The idea is to use Unicode characters like ÷ instead of HTML entities like &divide;, except in cases where characters can be confusing or there's an existing guideline to do something else (like with fractions and superscripts). If you'd like to read and/or comment, the latest version is at Wikipedia talk:Manual of Style § Fourth draft. Thanks! -- Beland (talk) 06:50, 10 August 2018 (UTC)

For heaven's sake, please, prevent any activists from adding more tabulated bureaucracy to the already enriched WP:MOS (e.g.: idiosyncratic "spacing of dashes"!). All the already stated precautions do apply fully to the draft, imho. Let's not have more of "I am an expert in the guidelines, which you constantly disrupt." and "I don't care a sh*t about you toiling to restore meaning, which is against (my) guidelines."
Why is it necessary to have so much canvassed into one go? Replacing hex-codes is a fine thing to do. I do not feel sufficiently prepared to comment directly on the MOS-TP. unintended copy on the science-project site Purgy (talk) 07:39, 10 August 2018 (UTC)
To Beland: Please let us have a complete list of the unicode characters which you propose that we should use in the source. How are we supposed to generate them? Anyone can easily type in "&" followed by "divide;", but how do I make the unicode divide character? What is the point of wasting our time doing this anyway? JRSpriggs (talk) 04:01, 11 August 2018 (UTC)

## Schröder–Bernstein theorem: OR or not?

A nice proof is added recently to "Schröder–Bernstein theorem" by KeesDoe, see here and here, and challenged by "citation needed". It is very easy to check the proof... can it survive unsourced? can it be sourced? Boris Tsirelson (talk) 10:16, 11 August 2018 (UTC)

IMO, this is a case of WP:IAR. This situation is rather frequent in mathematics, where some proofs and some results belongs to the common knowledge of the specialists, but are not sufficiently new for being the object of a publication, or were published a long time ago and cannot be retrieved by Google search. Moreover, a content is WP:OR, only if no source exists, not if no source is provided. In this case, it is unbelievable that no sources exist, although it may be difficult to find them. I have encountered the same problem many times when editing WP. Here are two examples. When editing Quartic function, I introduced a section on the nature of the roots. At that time, I did not know any source. A source in an article of 1922 has been provided later by a reader who discussed the slight difference between the two presentations. A second example, still unsourced was motivated by a discussion at Talk:Homomorphism#Inaccuracy (remainder) on the relationship between injections and surjections on a side and monomorphisms and epimorphisms on the other side. The main fact is that, in most (but not all) common cases, the two terminologies are equivalent, but I do not know a source giving explicitly a list of these cases. I have thus added collapsed proofs to Homomorphism for replacing missing sources. These proofs are certainly not new. My point of view about this example is a personal interpretation of the first paragraph of WP:Verifiability. The main point for WP is verifiability; this results normally from reliable sources, but, in mathematics, this may also result from a proof. D.Lazard (talk) 11:06, 11 August 2018 (UTC)
Rather convincing.
A kind of source: [1]. Boris Tsirelson (talk) 16:44, 11 August 2018 (UTC)
While a citation to this related result would be best, I agree with D.Lazard's point that it is difficult to source source every aside, especially if it seems routine or obvious to the experts. This could perhaps fall under the umbrella of routine derivation or common knowledge. That said, the problematic part is the language. Stating "It is easy to see that" is a challenge to the reader. This is good in a textbook where the author is a mentor encouraging readers to work it out for themselves. In WP, that sort of challenge just generates citation requests. --`{{u|Mark viking}} {Talk}` 18:36, 11 August 2018 (UTC)
In addition to needing an edit for math markup, the explanation could do with a little smoothing. For example, ${\displaystyle g}$ is at first the identity, but then ${\displaystyle g}$ denotes something else. XOR'easter (talk) 20:15, 11 August 2018 (UTC)
I'd agree with D.Lazard that obviously correct proofs are in doubt a case for WP:IAR. While providing reference in such cases would be better, simply deleting such correct proofs just because of missing reference is worse and disservice to readers.--Kmhkmh (talk) 20:36, 11 August 2018 (UTC)

## Draft:Journal of Combinatorial Algebra

Is this a notable journal (in the sense it can belong to mainspace)? -- Taku (talk) 23:31, 13 August 2018 (UTC)

Did you read the reason the draft was declined? The only real notability guideline for journals is WP:GNG (we also have WP:NJournals but that's just an essay). GNG requires in-depth coverage of the subject in multiple reliable published sources that are independent of the subject. For instance maybe someone wrote a section about the journal in a biography of one of its founders, and published it in another journal. Do you have sources like that? If so, add them to the article, and notability should become clear. If not, it is most likely not notable. —David Eppstein (talk) 00:14, 14 August 2018 (UTC)
No I didn't and I simply asked because I'm not familiar with the notability guidelines for the journals and so I was hoping the other members of the project to take a look at it. The question was not meant to be rhetorical here. -- Taku (talk) 00:23, 14 August 2018 (UTC)
I am regularly shocked by the low standards in practice for articles about journals. Like, here is an AfD I started about an article with 0 citations, and the only two votes so far are "keep". Anyhow, I asked about this journal here a year ago, you can see the feedback I got then. --JBL (talk) 01:16, 14 August 2018 (UTC)
Stop stealth canvassing. As for this journal, merge the first paragraph to European Mathematical Society and call it a day. Headbomb {t · c · p · b} 01:33, 14 August 2018 (UTC)

## Duodecimal

An IP editor is inserting masses of what looks to me to be original research at Duodecimal and reverting without comment whenever anyone (or at least me) tries to prune it back again. More eyes on the article would be helpful. —David Eppstein (talk) 01:14, 15 August 2018 (UTC)

Wow, this article is pretty bonkers even without that (it's around 150k!). The IP in question locates to Taiwan, and they've been fairly busy. I reverted some dubious additions at Unique factorization domain from the same editor, but they've edited from a number of different addresses and have been hitting some other articles as well. –Deacon Vorbis (carbon • videos) 02:16, 15 August 2018 (UTC)