Wikipedia talk:WikiProject Mathematics/Archive/2026/Apr

Catalan's constant

An editor has been adding material to Catalan's constant that include unsourced editorializations ("Using these series, calculating Catalan's constant is now about as fast as calculating Apéry's constant") and a "third formula" that, following the sources used for it, was found by someone with the same name as the editor (and is singled out from about 20 different formulas listed in OEIS). More eyes on the article would be welcome. —David Eppstein (talk) 23:55, 16 March 2026 (UTC)

I looked. The changes appear to be legit to me, but were reverted. They consisted of three refs, and the OEIS sequence. The "third formula" is "almost surely" legit; it is stereotypical of the kinds of formulas that Simon Plouffe has been churning out. I recognize them because I published a paper on something very similar. I've seen enough of these to suspect that there's some general formula/algo that can generate identities of this type, but I know not of any work pointing at such. linas (talk) 04:05, 1 April 2026 (UTC)

Finite cardinals and ordinals

It has come to my attention that we don't actually have much content regarding finite cardinal and ordinal numbers—that is, natural numbers considered as cardinals or as ordinals—anywhere. The lead of Ordinal number says that an ordinal number[...] is a generalization of ordinal numerals [...] aimed to extend enumeration to infinite sets. This implies that the article Ordinal numeral is about finite ordinals. However, Ordinal numeral is about words, and has a hatnote that says: For the mathematical concept, see Ordinal number. The situation with cardinals is better. Neither one of Cardinal number and Cardinal numeral suggests that the other one covers finite cardinals. We still have the problem that neither of them covers finite cardinals. The only place where either of these concepts seems to be covered is Natural number § Intuitive concept, and they are both covered there, but poorly.

This is not ideal. These concepts are important to a general audience of lay people, who are familiar with the terms "cardinal number" and "ordinal number", but get flummoxed when they encounter an article like Cardinal number or Ordinal number, since they expected an article about the finite case. To quote Beland, This is horribly confusing! I'm not volunteering to create this important content that we seem to be missing, but I'd like to hear your thoughts on where it belongs: in Cardinal number and Ordinal number, in Natural number, or in new articles dedicated for that? Streded (talk) 11:16, 28 March 2026 (UTC)

A somewhat uninformed opinion from the peanut gallery, but I think a section on natural numbers as finite cardinals vs ordinals would fit most naturally in the natural number article, which already does do some of the required work to distinguish counting things (cardinal number) from putting things into order (ordinal number). It only lacks a consolidated treatment. Sławomir Biały (talk) 11:22, 28 March 2026 (UTC)

Part of what drove me to write this is the realization that articles like Ordinal date link to Ordinal number: An ordinal date [...] consist[s] of a year and an ordinal number, ranging between 1 and 366 [...] representing the multiples of a day, called [...] ordinal day number... I want such articles to have a good target to link to. This makes me a little hesitant to relegate finite ordinals to a section that also discusses finite cardinals. Streded (talk) 11:53, 28 March 2026 (UTC)

I think a simple section like "ordinals and cardinals" could be useful to highlight both concepts and also the differences. I suspect there might be good sources from outside mathematics to help support it (e.g., philosophy), and there is no reason that a link from finite ordinal and finite cardinal can't be to the same section if both are treated in a unified way there. Sławomir Biały (talk) 12:01, 28 March 2026 (UTC)

Good point. If we do that, what should we do about the Intuitive concept section? It seems to be similar to what you're suggesting, but simultaneously more basic and way too abstract. Should that section link to the later section about ordinals and cardinals, instead of Cardinal number and Ordinal number as it currently does? Streded (talk) 12:12, 28 March 2026 (UTC)

I think the best thing to do would be to write the section first. After deciding what basic content to put there, then see if the existing article content should be lightly refactored if it reads as too redundant. Sławomir Biały (talk) 12:23, 28 March 2026 (UTC)

What you are suggesting belongs somewhere in Natural number. The articles Cardinal number and Ordinal number are about mathematical concepts closer to set theory and foundations, presented in a more rigorous fashion. General intuitive information about the finite case for a lay audience does not belong in these last two articles. PatrickR2 (talk) 21:22, 28 March 2026 (UTC)

I recall reading commentary, long ago, that many of the properties of the infinite cardinals/ordinals are reflected in the finite ones, as strange fun-house mirrors. For example, something about a finite analog to the Church-Kleene ordinal, about it getting really hard to find notation to write down ever-larger finite numbers (you can Knuth up-arrow only so far..) I don't recall any more than this, but having a good article on these would be pretty cool. linas (talk) 05:22, 1 April 2026 (UTC)

Include 2 in Category:Metric spaces

Category:Metric spaces is conspicuously incomplete without the empty metric space: the ordered pair whose underlying set is the empty set, S=∅, equipped with the unique function d:∅×∅→R (the empty function): (∅,∅)

Formally, it is straightforward to show that

(∅,∅) = {∅,{∅,∅}} = {∅,{∅}} = 2

⛬ $2\in Category:Metricspaces$

QED ເສລີພາບ (talk) 17:16, 1 April 2026 (UTC)

I don't think 'empty metric space' warrants a page, but we could have a page on the empty topology (or redirect to a section in Discrete space or Trivial topology). The Boolean^_Talk 19:10, 1 April 2026 (UTC)

The empty metric space would have the base space the empty set M={}. The domain of the distance function would be the Cartesian product of the empty set with itself which is also the empty set. So the distance function d={}. So the metric space would be (M,d)=({},{})={{{}},{{},{}}}={{{}}}={1}≠2. This is too trivial to be worth mentioning in the article. JRSpriggs (talk) 20:12, 1 April 2026 (UTC)

You are correct. I missed a bracket. This is quite embarrassing and I'm not sure what to do now. ເສລີພາບ (talk) 20:41, 1 April 2026 (UTC)

Personally I think the particular encoding of Peano arithmetic in set theory is spurious and using it to say things like "2 is a metric space" is a type error. Sesquilinear (talk) 20:38, 1 April 2026 (UTC)

Exactly my opinion as well. —David Eppstein (talk) 22:25, 1 April 2026 (UTC)

Calculus

Do we need any further improvements to this article especially the history section as well as to the History of Calculus article, in order for it to be nominated to B-class Myuoh kaka roi (talk) 18:51, 27 March 2026 (UTC)

B-class does not involve a nomination process; anyone can judge the article to be B-class (or not) and change the assessment. If there is disagreement we can have a discussion on the article talk page. —David Eppstein (talk) 19:17, 27 March 2026 (UTC)

I think B-class is probably a fair assessment. But to my mind the biggest problems are in the Applications section. I don't have any ideas how one would write such a section, but the examples are weirdly scattershot. Calculus is basically used in every quantitative discipline to a greater or lesser extent, and picking up population dynamics as the application of calculus to biology, or Black-Sholes as the application to finance, seems highly suspect. Just reaction rates and radioactive decay in chemistry? Even the physics, which fares a little bit better, is not really good. (e.g., what about thermodynamics/statistical mechanics? quantum mechanics? or... basically anything else.) The problem is that there is no way to give an exhaustive account, but any attempt to drill down starts to look cherry-picked to a greater or lesser extent. [/steps off soapbox] Sławomir Biały (talk) 19:35, 27 March 2026 (UTC)

Anything about History of Calculus article? And I strongly agree that the application section need to be heavily improved Myuoh kaka roi (talk) 19:44, 27 March 2026 (UTC)

I would rate this still as 'C' class. (Remember, the point of the ratings is to help editors prioritize their attention, not to pat ourselves on the back.) It seems pretty undeveloped for such an important topic; we should be trying to give an overview of calculus in all of its various manifestations, rather than just cover a few results from an introductory course. As just one obvious example, there should be more than 1–2 sentences about the topic of differential equations, which are central to all modern science. –jacobolus (t) 19:42, 27 March 2026 (UTC)

Agree with @Jacobolus, but my opinion on the overview of calculus is different. The article should discuss by its subfield, like differential calculus, integral calculus, multivariable calculus, and vector calculus. Differential calculus scopes the limit of a function, which is the basic concept before the derivative of a function and its application. The same thing for integral calculus, which includes the Riemann sum, integrals (definite, indefinite, and improper) and series. And et cera for other subfields. Renaming them numerically like "Calculus I", "Calculus II", and "Calculus III" confines the others like fractional calculus, Malliavin calculus, stochastic calculus, and calculus of variations. As Jacobolus said, we should give an overview of each subfield instead of the definition and theorem, or any concept written formally. Dedhert.Jr (talk) 01:34, 28 March 2026 (UTC)

And for the additional note: Some various calculus can be included in a certain subfield, like stochastic calculus in differential calculus. Dedhert.Jr (talk) 01:39, 28 March 2026 (UTC)

I don't understand what Calculus III, etc. are supposed to mean. –jacobolus (t) 02:14, 28 March 2026 (UTC)

A separating huge amount of calculus topics, according to university classes. Dedhert.Jr (talk) 02:36, 28 March 2026 (UTC)

The contents of our article Calculus should not be determined by the contents or organization of university courses titled "Calculus". –jacobolus (t) 03:33, 28 March 2026 (UTC)

Got it. "Differential calculus", "Integral calculus", "Multivariable calculus", and "Vector calculus" should be the main subfields of calculus. We can write the remaining somewhere else. Those numerically based already exist as redirect articles. Dedhert.Jr (talk) 03:40, 28 March 2026 (UTC)

"Multivariable calculus" and "vector calculus" are basically synonyms. We should also have significant coverage about differential equations, real and complex analysis, numerical analysis, the calculus of variations and functional analysis, maybe matrix calculus, probably some about distributions, etc. –jacobolus (t) 03:57, 28 March 2026 (UTC)

I have started an expansion along those lines. Stepwise Continuous Dysfunction (talk) 07:41, 28 March 2026 (UTC)

Thanks, that looks great! –jacobolus (t) 18:55, 29 March 2026 (UTC)

Calculus § Applications still needs work. Stepwise Continuous Dysfunction (talk) 05:33, 1 April 2026 (UTC)

I tried making some "local" improvements to Calculus § Applications, and perhaps it no longer reads as quite so arbitrary and miscellaneous, but perhaps a more "global" rethinking would help. Stepwise Continuous Dysfunction (talk) 01:51, 2 April 2026 (UTC)

Mathematics has an RfC

Mathematics has an RfC for possible consensus. A discussion is taking place. If you would like to participate in the discussion, you are invited to add your comments on the discussion page. Thank you. GeogSage ^{(⚔Chat?⚔)} 23:15, 30 March 2026 (UTC)

Speaking of which, there's an article about mathematics on Wiktionary with a short explanation. What do you think about that?--SilverMatsu (talk) 16:21, 1 April 2026 (UTC)

The first clause seems a bit awkward and the definition as a whole is too long for a short description; I think, for what short descriptions are actively useful for, "field of study" is probably perfectly fine anyways.

Regardless, probably better to use the talk page for that sort of discussion. Sesquilinear (talk) 23:11, 1 April 2026 (UTC)

Thank you for your reply. Does "talk page" refer to the Wikipedia talk page discussing short descriptions, or the Wiktionary talk page?--SilverMatsu (talk) 01:17, 2 April 2026 (UTC)

I was referring to discussion about the short description, so Talk:Mathematics. Sesquilinear (talk) 01:21, 2 April 2026 (UTC)

Thank you for clarifying.--SilverMatsu (talk) 05:33, 2 April 2026 (UTC)

24-cell

See discussion in Talk:24-cell#Excessive citations. I don't think I have time to deal with these footnotes, and I'm almost giving up because of the tables with multiple footnotes, which are useful. I could only trim unsourced sections. Should have named the title "footnotes" instead of "citations". 😞. Dedhert.Jr (talk) 12:03, 2 April 2026 (UTC)

As for reminder, some sections in 24-cell do have a good explanation of some technical terms. Specifically, for the rotations, it is preferable to improve Rotations in 4-dimensional Euclidean space. Dedhert.Jr (talk) 12:08, 2 April 2026 (UTC)

"Surely it can't be that much, I'm about to go take a nap but out of curiosity I'll give it a look", I said to myself, clueless.

"Excessive footnotes" does not nearly do it justice. The footnotes are nested fractal. There are nearly twice as many words in the footnotes as in the article proper. How did this come to pass??? MEN KISSING (she/they) Talk to me, I don't bite! - See my edits 13:45, 2 April 2026 (UTC)

It used to be even worse. —David Eppstein (talk) 16:21, 2 April 2026 (UTC)

Whoever made this has a bright future in the cosmic horror genre. I'm certainly more shaken than I expected to be. Streded (talk) 17:52, 2 April 2026 (UTC)

The Wikiversity article on the 24-cell still goes up to fx. Sesquilinear (talk) 22:15, 2 April 2026 (UTC)

The citations are also broken in the Notes section. The Boolean^_Talk 21:14, 2 April 2026 (UTC)

I think the fundamental problem is that these were made as the idiosyncratic record of one person's personal research project rather than by trying to summarize the content of existing reliable sources. The resulting page(s) have some interesting and even insightful features, but they are hard to work on collaboratively in the style of typical Wikipedia articles. –jacobolus (t) 21:36, 2 April 2026 (UTC)

In that case, it might be best to just delete these sections and develop the page from there. I agree that much of the information is interesting, but it would take longer to sift through to see what's sourced and what's worthy of the article than to write a new section. The Boolean^_Talk 21:54, 2 April 2026 (UTC)

Agreed, Wikipedia footnotes are not supposed to be a place for original survey papers. Elestrophe (talk) 22:54, 2 April 2026 (UTC)

I took the bold, perhaps excessive, step of cutting out the editorial footnotes entirely. It's better to build them up as needed based on what books and articles say about the 24-cell than try to cut a passion project down to size one step at a time, particularly when the footnote graph is cyclic. I have also lightly edited the opening paragraphs for clarity. Stepwise Continuous Dysfunction (talk) 23:32, 2 April 2026 (UTC)

Honestly I was thinking of doing the same thing. I just didn't have the heart for it. MEN KISSING (she/they) Talk to me, I don't bite! - See my edits 23:45, 2 April 2026 (UTC)

Wikipedia:Articles for deletion/Deterministic context-free grammar

This AfD is getting out of hand. I feel like this, as the nominator is acting uncivilly toward other users who disagree with their claim. It requires evaluation of assertions that the topic is ill-defined or nonsensical, including which was raised by a user at the talk page in 2014. –LaundryPizza03 (dc̄) 05:46, 3 April 2026 (UTC)

References

Two pages that do not exist

Hi everyone!

I was reading the early mathematical work described in the biographies of Artur Avila and Fernando Codá Marques. They mentioned the Zorich–Kontsevich conjecture (in dynamical systems, 778 results on a Google search) and the Min-Oo conjecture (in differential geometry, 3520 results on Google searching for "Min-Oo" + "conjecture") respectively.

I've added them to Wikipedia:Requested articles/Mathematics. Is anyone interested in starting any of them? I think it would be nice! The Zorich–Kontsevich conjecture statement seems very technical, accessible only to specialists in dynamical systems, but Min-Oo's conjecture seems way more interesting and understandable: https://arxiv.org/pdf/2308.03184

Best, Is Johnson (talk) 17:01, 4 April 2026 (UTC)

Notable assistant/associate professors of mathematics

I want to start articles on notable (by WP:GNG or WP:PROF criteria) assistant or associate professors of mathematics. Today I've started the article about Yevgeny Liokumovich. I am planning on starting one about Elina Robeva later (she was awarded the Aisenstadt Prize in 2023). Please, I would greatly appreciate receiving suggestions of names of notable mathematicians that are not full professors yet. A bonus if they are from poor countries or from other underrepresented groups in mathematics, such as women, for example). Thank you! MathKeduor7 (talk) 21:53, 6 April 2026 (UTC)

Young researcher awards such as the Aisenstadt Prize are often not enough to pass WP:PROF#C2, and for junior faculty there may not be much else yet as indicators of notability. For junior faculty who do not even have these awards, the usual outcome is that they are not considered notable. When you make articles on these people, please start already having in mind what additional evidence you might use to persuade people that they are notable, if you need to persuade them (for instance in an AfD or after an article gets draftified). It needs to be evidence that can be seen and evaluated by non-mathematician Wikipedia editors, such as society fellowships or awards that are not labeled as being for early career researchers. See Wikipedia:Articles for deletion/Si Ying Lee for a case of someone who received an early-career award that I think is more significant than the Aisenstadt Prize (for one thing it is international rather than specific to one country) but was deemed not yet notable in an AfD. We should try to avoid outcomes like that one, because it makes it much more difficult to make an article later even when more evidence of notability has built up.

This is one of the reasons that I prefer creating articles on older and more-established academics (often at the full professor level already). Even for those, there needs to be more justification for notability than a single award that could be argued away as minor and local. —David Eppstein (talk) 22:25, 6 April 2026 (UTC)

Thank you for your reply Professor David Eppstein! I'll embark on other projects at Wikipedia then. By the way, Elina Robeva seems to be highly-cited enough (I don't know, maybe Wikipedia requires more), but I won't start an article on her, as I fear someone would send it for deletion. I wish good edits for everyone! MathKeduor7 (talk) 23:01, 6 April 2026 (UTC)

If you start from the other end of the list you might find more well-established but neglected mathematicians who deserve articles. The earliest Aisenstadt Prize winner without an article, Ian F. Putnam, is clearly notable as an FRSC and Fellow of the AMS (double pass of WP:PROF#C3), for instance. —David Eppstein (talk) 23:59, 6 April 2026 (UTC)

I am going to start an article about him in a few days (and maybe of other Fellows of the AMS)! I need to go to sleep now and I won't have time to edit Wikipedia for a few days. I am very tired right now, but I have two questions: Do you think the Simons Fellowship is enough to pass WP:PROF? If not, should I move the article about Liokumovich to the draft namespace or maybe to a subpage in my user page? (before someone tries to delete it, and so that I could be improving it over time until the notability becomes clear). I think that co-solving an important conjecture by Gromov should be enough for notability, but we are at Wikipedia! Haha ^^. MathKeduor7 (talk) 01:00, 7 April 2026 (UTC)

TWAS fellows working in mathematical sciences might be worth checking: . fgnievinski (talk) 01:02, 7 April 2026 (UTC)

It's a bit off topic, but is there a list anywhere of relatively prominent mathematicians who should clearly have a Wikipedia article but are currently red links? (I'm thinking about people with named chairs, editors of major journals, have had Festschrifts, won major prizes, have many highly cited papers and lots of students, etc.) –jacobolus (t) 02:58, 7 April 2026 (UTC)

Wikipedia:WikiProject Women in Red/Mathematics has some. Stepwise Continuous Dysfunction (talk) 03:25, 7 April 2026 (UTC)

There are a few redlinks at List of presidents of the Institute of Mathematical Statistics and List of members of the National Academy of Sciences (applied mathematical sciences). Stepwise Continuous Dysfunction (talk) 03:30, 7 April 2026 (UTC)

There are a lot of redlinks (all male, I think, if that's relevant for you) at Category talk:Fellows of the American Mathematical Society. —David Eppstein (talk) 05:23, 7 April 2026 (UTC)

Also a lot of redlinks at List_of_International_Congresses_of_Mathematicians_Plenary_and_Invited_Speakers. jraimbau (talk) 20:14, 7 April 2026 (UTC)

Related --- it'd be nice to have the list of speakers on that page separated into plenary and invited lectures.

It might also be nice to separate the invited speakers by section, but that might make it too cluttered, especially since some are cross-listed in multiple sections. Gumshoe2 (talk) 21:20, 7 April 2026 (UTC)

i think those red link mathematicians at Mathematical Society of Japan deserve articles (as the prizes by the MSJ are prestigious). It's quite possible there are already articles on some of them in Japanese Wikipedia; just not here in English Wikipedia Taku (talk) 20:41, 8 April 2026 (UTC)

Question about Lucas primality test

In the example in Lucas primality test, it says "We randomly select an a=17 < n." Does a have to be relatively prime to n? Bubba73 ^{You talkin' to me?} 22:59, 8 April 2026 (UTC)

No. If a is not coprime to n, then n is composite. I think that the test would still work, even if you do not bother to check for coprimeness. You can check that easily by calculating the greatest common divisor of a and n. If it is not 1, then they are not coprime and it is a divisor of n, i.e. a witness that n is not prime. JRSpriggs (talk) 23:28, 8 April 2026 (UTC)

If ⁠$d$⁠ divides both ⁠$a$⁠ and ⁠$n$⁠, then is divides also ⁠$a^{n-1}$⁠. So, the first part of the test provides "composite". D.Lazard (talk) 13:44, 9 April 2026 (UTC)

scr

I have just added a citation to this paper https://www.sciencedirect.com/science/article/pii/S0021869314004505 to Hyperoctahedral group. Unfortunately the title seems to use the script font \scr that isn't supported here (maybe?). Currently I've swapped it for \mathcal. Does anyone have a better suggestion about how to handle this? --JBL (talk) 18:34, 6 April 2026 (UTC)

𝓐𝓑𝓒𝓓𝓔𝓕𝓖𝓗𝓘𝓙𝓚𝓛𝓜𝓝𝓞𝓟𝓠𝓡𝓢𝓣𝓤𝓥𝓦𝓧𝓨𝓩 Sławomir Biały (talk) 18:42, 6 April 2026 (UTC)

Thank you! --JBL (talk) 18:44, 6 April 2026 (UTC)

I think using mathcal is fine, but in case one day you really need mathscr, note that unicode supports it:

𝒜 ℬ 𝒞 𝒟 ℰ ℱ 𝒢 ℋ ℐ 𝒥 𝒦 ℒ ℳ 𝒩 𝒪 𝒫 𝒬 ℛ 𝒮 𝒯 𝒰 𝒱 𝒲 𝒳 𝒴 𝒵

Malparti (talk) 03:02, 10 April 2026 (UTC)

The Unicode "MATHEMATICAL SCRIPT" symbols are usually rendered as similar to "mathcal". There's no separate "caligraphic" vs. "script" symbols, though presumably you could have separate fonts with each type of lettering, using the same unicode code points, or even one font including multiple variant glyphs for each code point. –jacobolus (t) 03:52, 10 April 2026 (UTC)

The PDF of the paper itself uses mathcal ⁠${\mathcal {W}}$⁠, so that should be fine. The flowery script font seems to be a buggy artifact of the web-based presentation on ScienceDirect. Depending on whether you prefer LaTeX or a math template, I'd write one of:

• Wilson, Jennifer C.H. (2014), "⁠$\mathrm {FI} _{\mathcal {W}}$⁠-modules and stability criteria for representations of classical Weyl groups", Journal of Algebra, 420: 269–332, doi:10.1016/j.jalgebra.2014.08.010
• Wilson, Jennifer C.H. (2014), "FI_𝒲-modules and stability criteria for representations of classical Weyl groups", Journal of Algebra, 420: 269–332, doi:10.1016/j.jalgebra.2014.08.010

You shouldn't use a bold symbol in the subscript, as currently done. –jacobolus (t) 19:00, 6 April 2026 (UTC)

That's extremely odd. I had actually pulled the tex code from MathSciNet, so it's somehow more than just a bug of the presentation at Science Direct. I have opted to go back to the LaTeX version (which also matches the author's other papers on this topic). --JBL (talk) 18:22, 9 April 2026 (UTC)

Requested move at Talk:List of misnamed theorems#Requested move 27 March 2026

There is a requested move discussion at Talk:List of misnamed theorems#Requested move 27 March 2026 that may be of interest to members of this WikiProject. TarnishedPath^talk 10:40, 10 April 2026 (UTC)

EoM blocked?

Apologies if this has been raised already, but is Springer EoM globally down/blocked, or is it just from my location? (E.g.: .) I haven't tried accessing it with a VPN, but haven't been able to access it for several weeks from my location. It might be useful for someone with the right archive-bot-fu to add wayback links if this issue persists and isn't geographically limited. Sławomir Biały (talk) 11:13, 10 April 2026 (UTC)

I wouldn't expect "Error: Server Error" if it was blocked. -- Shmuel (Seymour J.) Metz Username:Chatul (talk) 13:34, 10 April 2026 (UTC)

I've been getting 502 errors myself for a while now. Sesquilinear (talk) 19:04, 10 April 2026 (UTC)

Same for me (from Berlin) and the root page https://encyclopediaofmath.org - Jochen Burghardt (talk) 22:00, 10 April 2026 (UTC)

From my Japan ip address, I can’t access the site either (got the server error). Maybe a temporary outage (if temporary is meant several weeks). Taku (talk) 02:31, 11 April 2026 (UTC)

Put "is encyclopediaofmath.org down" into Google to see that this apparently is a known problem. Johnuniq (talk) 03:19, 11 April 2026 (UTC)

I'd generally recommend citing the physical paper edition. The online edition is rarely if ever non-trivially different anyway, and doesn't seem to have been very actively worked on. –jacobolus (t) 03:44, 11 April 2026 (UTC)

The advantage used to be that it was easily accessible. I think someone should look into adding wayback links. Sławomir Biały (talk) 05:08, 11 April 2026 (UTC)

I thought the paper copies had scans on the Internet Archive, but apparently not. Perhaps they were removed. –jacobolus (t) 05:26, 11 April 2026 (UTC)

Yeah, my issue wasn't so much whether one could in principle access the paper copies. It's that a completely electronic link to a single light-weight web page: it's not so much a problem of WP:V as it is one of reader (and editor!) convenience. For example this is a wayback link of the above article, much more convenient than having to download an entire scanned pdf of a very large book. However, looking at the wayback link, it seems less than ideal because the latex/mathjax doesn't seem to render at all for me. Still, I guess it would be better than getting a 502 error. Sławomir Biały (talk) 05:35, 11 April 2026 (UTC)

Update: they are there after all (but "borrow unavailable", so you can search inside but only view one or two pages). I was spelling it as "encyclopedia" rather than "encyclopaedia" in my search. E.g. volume 1, all volumes. –jacobolus (t) 05:50, 11 April 2026 (UTC)

Grothendieck's relative point of view

I believe the notion described in this article certainly exists, but I think this article needs more references. There seem to be few references that specifically explain Grothendieck's relative point of view.--SilverMatsu (talk) 16:09, 11 April 2026 (UTC)

Category:Metric linear spaces has been nominated for discussion

Category:Metric linear spaces has been nominated for possible deletion, merging, or renaming. A discussion is taking place to decide whether it complies with the categorization guidelines. If you would like to participate in the discussion, you are invited to add your comments at the category's entry on the categories for discussion page. Thank you.

It is a highly technical subject and the discussion hinges on the subject matter. –LaundryPizza03 (dc̄) 07:44, 13 April 2026 (UTC)

Initial segment

Hi, all. There has been a debate as to whether this new article initial segment is a content fork of the existing upper set (an initial segment is also called a lower set) or not. David Eppstein thinks it is while I disagree or rather there is a room for a separate article for the use in set theory. We are at deadlock in the debate and thus can appreciate third opinions, comments, etc. at Talk:Initial segment. Taku (talk) 23:26, 13 April 2026 (UTC)

Capitalization of de La Vallée Poussin

See Talk:Charles Jean de la Vallée Poussin for a move proposal regarding the mathematician who proved the prime number theorem. —David Eppstein (talk) 19:24, 15 April 2026 (UTC)

Participant List

Hi, I just joined so I was just looking at the Participant List. There are lots of names outside of the prescribed alphabetical order. Should this be changed or just left alone? Thank you. SailorKuu (talk) 22:32, 16 April 2026 (UTC)

@SailorKuu. Can you tell what Participant List you are referring to? Dedhert.Jr (talk) 01:55, 17 April 2026 (UTC)

This one: Wikipedia:WikiProject_Mathematics/Participants. @SailorKuu, you can alphabetize it if you want. I don't think anyone pays much attention to that list; many of the common participants here are not listed, and most of those listed are inactive. –jacobolus (t) 02:04, 17 April 2026 (UTC)

With a lot of these names, I feel like Obi Wan "There's a name I haven't heard in a long time." Sławomir Biały (talk) 10:32, 17 April 2026 (UTC)

I think that sorting the list is a great idea. I did not add my user-id because I could not figure out where to add it. But what about capitalization, how should that affect the sort? Should we just sort on the user-id itself or on the person's full name? JRSpriggs (talk) 11:59, 17 April 2026 (UTC)

"one of the greatest living mathematicians" is encyclopedic tone?

Hello. There is one thing that bothers me: I've seem many articles tell some mathematician is one of the greatest living or even greatest of the century and things like that... For example, Terence Tao's article says he "is widely regarded as one of the greatest living mathematicians". I think this is essentially correct, but it's nonetheless meaningless and not written in an encyclopedic tone. I did not dare to remove it, because it cites five sources to support it. But why meaningless? Well, it doesn't convey any useful information, also because: Is he among the top 100? Maybe the top 50? There are many impressive Fields Medallists, Abel Prize winners, Wolf Prize winners, etc... who are still alive. Should we mention at Jean-Pierre Serre, Andrew Wiles, Peter Scholze, Grigori Perelman, John Milnor, Mikhael Gromov, Stephen Smale and so on that they are among the greatest living mathematicians? I think not. Maybe there is some Wikipedia policy already about things like this? Pentakol (talk) 02:13, 16 April 2026 (UTC)

I think "widely regarded" and "one of the" does make it encyclopedic. We don't have to pick the cut-off mark for top-N as "greatest", we just have to find enough secondary sources that make that claim. Tao is particularly popular so I am not surprised that there were multiple citations available for that claim but that doesn't stop us from making the claim for other mathematicians if we can find citations for it. abandeali (talk) 02:42, 16 April 2026 (UTC)

I think saying "widely regarded as greatest" is different than saying "greatest" since the former is stating what many believe which appears to be notable for Terence Tao's case while the latter is unencyclopedic since it is not neutral. EulerianTrail (talk) 14:58, 16 April 2026 (UTC)

I definitely agree with you. I think it's unprofessional and unfair to many other mathematicians, including those you mention, that Tao's popularity in the media allows this to be so easily cited. Notably, it would be just as easy to cite that his fellow mathematicians call him the "Mozart of math" despite this being, as far as the evidence shows, purely a media creation. Gumshoe2 (talk) 14:37, 16 April 2026 (UTC)

It seems to me obviously encyclopedic information that something is widely regarded as an exceptional example. I could imagine that in some cases it could be done as at Emmy Noether ("Noether was described by Pavel Alexandrov, Albert Einstein, Jean Dieudonné, Hermann Weyl, and Norbert Wiener as the most important woman in the history of mathematics. As one of the leading mathematicians of her time ...") but it doesn't strike me as particularly worse that Mike Schmidt is "widely considered to be one of the greatest third basemen in baseball history" or that Pelé is "[w]idely regarded as one of the greatest [soccer] players in history" or that John Maynard Keynes is "known as the "father of macroeconomics" and is one of the most influential economists of the 20th century". --JBL (talk) 19:33, 16 April 2026 (UTC)

Are there any available examples for contemporary figures, especially academics? I think it's very different for figures from past times where there is plenty of available retrospective commentary. Gumshoe2 (talk) 19:59, 16 April 2026 (UTC)

LeBron James: "James is widely considered to be one of the greatest basketball players of all time" abandeali (talk) 20:16, 16 April 2026 (UTC)

There are some about Paul Erdős Erdős that describe him as the greatest among the century he lived. EulerianTrail (talk) 21:18, 16 April 2026 (UTC)

Hi. I am here at the invitation of a friend. Well, about the matter: Every Fields Medal winner alive today is "widely regarded as one of the greatest living mathematicians". Just as every Nobel Prize in Physics winner alive today is "widely regarded as one of the greatest living physicists". There is no need for MOS:PEACOCK language in the articles about them. Just describe Tao's main contributions to mathematics and the major prizes he won. An encyclopedia should be about facts, not opinions. By the way, one of the references given there for the claim https://newsroom.ucla.edu/releases/Terence-Tao-Mozart-of-Math-7252 is a quote by John Garnett, who said "He’s an incredible talent, and probably the best mathematician in the world right now." This is very different from "widely regarded as one of the greatest living mathematicians", it's the opinion of one person and uses the word "probably", so it doesn't source our article's claim. All the references for that claim need to be checked, and maybe the phrase should be reworded or even completely removed. Just my two cents. JLW57 (talk) 12:44, 17 April 2026 (UTC)

Every Fields Medal winner alive today is "widely regarded as one of the greatest living mathematicians". This seems ... definitely wrong? You should test-drive it by a few mathematicians and see if they agree. Certainly it is not verifiable in reliable sources, unlike the statement about Tao (and Schmidt, and Pele, and Noether, and Keynes). probably the best is very similar to one of the greatest; to the extent it's different, it's actually more effusive. The beginning of WP:PEACOCK is ... used without attribution to promote the subject of an article, while neither imparting nor plainly summarizing verifiable information but here the information is certainly verifiable and is being plainly summarized. --JBL (talk) 17:21, 17 April 2026 (UTC)

We can also add (with reliable sources to support the adjectives) that Tao is one of the most famous and influential mathematicians today. Let's add that to his article? There are many other adjectives that can be added and backed by reliable sources ("one of the most decorated", by number of prizes received, for example), one of the most generous with his time (yes)... Not everything that has a source should be added to his article, if we do that it will become ridiculous, specially when it clearly adds nothing (after we tell of his great contributions to mathematics and that he received the Fields Medal, why add that he is great?). It's a bad habit, maybe due to how common it is for fans and commentators of sports to do that? Btw, Lionel Messi once said he never saw Pelé playing (not even videos!). Mathematics and soccer are very different things. Everyone here in this forum has heard about Hilbert or Poincaré. In two hundred years many people will still remember Euclid, Archimedes, Newton, Euler, Gauss, Hilbert, Poincaré, and learn from them directly (by reading them) or indirectly, but no one will care about Pelé or Messi (or some baseball or basketball player): They were people who played sports, had success on them, got famous and rich, but they are not important as Tao, who still will be remembered for years to come. :) P.S. At least one source was removed from there, as it was not of high-quality enough for the claim, and did not support the claim. Well, I have better things to do than discuss this here. I'm not going to interfere. JLW57 (talk) 18:30, 17 April 2026 (UTC)

The facts that Tao is widely esteemed and that particular mathematicians have said superlatives about him are just facts that we can document. So, there's not a problem in principle with language like "widely recognized as a generational talent" or "widely regarded as one of the greatest". I am, however, somewhat dissatisfied with the details of how the Terence Tao article actually does this. First, I'd drop the UCLA newsroom source; that's Tao's university reporting statements by other people who work at Tao's university, i.e., not independent by any margin. Second, the main text of the article doesn't do a very good job of following up on that line. It has a whole subsection about "Recognition", but that just lists a bunch of awards and gives a couple quotes, not really fleshing out the "widely regarded as one of the greatest" statement. If I see in the intro that he is "widely regarded as one of the greatest living mathematicians", and what I see in the article below is that he was an Australian of the Year finalist in 2007, have I learned anything about why mathematicians esteem him? No, no I have not.

So, I don't think there's a fundamental problem, but there are issues of implementation. Stepwise Continuous Dysfunction (talk) 18:29, 17 April 2026 (UTC)

OK, I moved some things around and tried to write an intro paragraph that conveys more about his career. The superlative is now down below and attributed rather than in wiki-voice. Stepwise Continuous Dysfunction (talk) 19:02, 17 April 2026 (UTC)

I find it very satisfactory now, thanks for your edit. Gumshoe2 (talk) 19:20, 17 April 2026 (UTC)

Requested move at Talk:Body relative direction#Requested move 6 April 2026

There is a requested move discussion at Talk:Body relative direction#Requested move 6 April 2026 that may be of interest to members of this WikiProject. TarnishedPath^talk 07:26, 20 April 2026 (UTC)

Some mathematicians bios drafts

Drafts about mathematicians who won blue-linked prizes (or whose drafts say they won):

• Draft:François Delarue
• Draft:Iosif Polterovich
• Draft:Rajula Srivastava
• Draft:Yu Deng
• Draft:Valentin Blomer
• Draft:Otis Chodosh
• Draft:Semyon Dyatlov
• Draft:Zsolt Páles
• Draft:Evgeny Plotkin
• Draft:Mikaela Iacobelli
• Draft:Carina Hong
• Draft:Christoph Schweigert

Some of them may be notable. TammKask (talk) 16:01, 19 April 2026 (UTC)

Yes, I would say that most of these are notable under WP:PROF. Sławomir Biały (talk) 05:18, 20 April 2026 (UTC)

I added those drafts to the Wikipedia:WikiProject Mathematics/List of math draft pages.--SilverMatsu (talk) 23:47, 20 April 2026 (UTC)

Issues with supermanifold

See online discussion at . The article is badly sourced, with problematic definitions, and maybe comes from too much of a physics background to get the mathematics right. I don't understand any of this well enough to make a useful contribution to the article but I hope someone else here does. —David Eppstein (talk) 05:39, 21 April 2026 (UTC)

Markowsky's theorem

According to Thomas & Williams (2019), there appears to be another theorem other than Markowsky's (1976) called Markowsky's theorem. Would I split the article?--SilverMatsu (talk) 03:36, 20 April 2026 (UTC)

If there are two notable theorems by the same name then they should have two separate articles with disambiguated titles. —David Eppstein (talk) 05:11, 20 April 2026 (UTC)

Thank you. It might be better to change the title of Markowsky's theorem to Markowsky's theorem (order theory) or Markowsky's theorem (domain theory), and create a article(draft) such as Markowsky's theorem (lattice theory) or Markowsky's representation theorem.--SilverMatsu (talk) 23:43, 20 April 2026 (UTC)

Those names all seem reasonable to me. I would prefer to avoid the lattice name, though, because of the confusion between order-theoretic lattices and group-theoretic lattices. —David Eppstein (talk) 05:40, 21 April 2026 (UTC)

I moved Markowsky's theorem to Markowsky's theorem (order theory) and created Draft:Markowsky's representation theorem.--SilverMatsu (talk) 01:22, 22 April 2026 (UTC)

It appears the Dab page has been reverted to redirecting to Markowsky's theorem (order theory) because Draft:Markowsky's representation theorem is not yet an article. If the Dab page does not exist, Markowsky's theorem (order theory) may be reverted to Markowsky's theorem as an unnecessary parentheses/disambiguator.--SilverMatsu (talk) 01:59, 23 April 2026 (UTC)

I agree with the revert that it is unnecessary to have a disambig page yet. We can always create it after the draft article is moved to mainspace. Taku (talk) 09:11, 23 April 2026 (UTC)

Wikipedia:Articles for deletion/EML (mathematical operator)

This discussion could probably use more input. Stepwise Continuous Dysfunction (talk) 19:59, 24 April 2026 (UTC)

Really shouldn't have been relisted; 3 clear arguments for deletion, one non-policy keep, and three comments that all agree that there's no RS coverage. --JBL (talk) 20:35, 24 April 2026 (UTC)

Probabilistic logic network

The article Probabilistic logic network had its notability questioned years ago on its Talk page, and it's been tagged for quite a while. As written, it seems to cover an AI-related proposal that hasn't really gone anywhere substantial. Many of the Google Scholar hits for the term appear to be about something else (e.g., they don't name the authors who published this idea). The two sources are primary; one of them is the researchers' own wiki, which has since been edited to say that the idea "has been abandoned as of 2021". I don't think we need to document abandonware that was only ever dubiously notable in the first place. So... What should be done with it? Just put it up for deletion? Find somewhere it could be redirected? Stepwise Continuous Dysfunction (talk) 01:49, 20 March 2026 (UTC)

I would be in favor of putting it up for deletion. Malparti (talk) 10:30, 20 March 2026 (UTC)

See now Wikipedia:Articles for deletion/Probabilistic logic network. Stepwise Continuous Dysfunction (talk) 22:43, 20 March 2026 (UTC)

This has been open for about six days now without attracting any !votes one way or the other. Stepwise Continuous Dysfunction (talk) 01:10, 27 March 2026 (UTC)

This was relisted the other day. Further input welcome. Stepwise Continuous Dysfunction (talk) 23:37, 1 April 2026 (UTC)

This is still open, if anyone's interested. Stepwise Continuous Dysfunction (talk) 22:56, 10 April 2026 (UTC)

... Never mind, it's been closed as "no consensus", meaning that despite most of the comments being opposed in one way or another to it existing, it just sits there. Stepwise Continuous Dysfunction (talk) 02:26, 11 April 2026 (UTC)

I missed this discussion, but after reviewing the article and the AfD, I have WP:BLARed Probabilistic logic network. --JBL (talk) 18:24, 25 April 2026 (UTC)

Yoneda extension

Which is a better place to explain this notion: Yoneda's lemma or Kan extension?--SilverMatsu (talk) 15:07, 25 April 2026 (UTC)

I think the Yoneda lemma, since the Kan extension is an extension along any map not just an embedding. Taku (talk) 23:24, 25 April 2026 (UTC)

Thank you for your reply. Done.--SilverMatsu (talk) 23:58, 25 April 2026 (UTC)

Currently, the Yoneda extension seems to be a redirect to the Presheaf (category theory)#Universal property. Would it be better to change the redirect target?--SilverMatsu (talk) 04:19, 27 April 2026 (UTC)

Unreliable source?

Special:Search/"The Universal History of Numbers": I am not sure articles should be citing this book. See Georges Ifrah and in particular https://www.ams.org/notices/200201/rev-dauben.pdf. 1234qwer1234qwer4 21:16, 21 April 2026 (UTC)

There are also "From+One+to+Zero"+"Ifrah" several citations to From One to Zero, apparently an earlier version of the same book. —David Eppstein (talk) 21:58, 21 April 2026 (UTC)

I think the book can be cited in some contexts, but we should take care about it. Where possible it's of course preferable to cite books about history and science written by subject-expert scholars rather than mass-market books written by nonspecialists. –jacobolus (t) 22:08, 21 April 2026 (UTC)

Resources by nonexperts are certainly acceptable (though not ideal). If the review is to be believed, however, Ifrah's book isn't just written by a nonexpert. It has serious issues, even outright fabrications. The Boolean^_Talk 01:47, 22 April 2026 (UTC)

I think it's more a matter of sloppiness than intentional "fabrication". If you get someone who doesn't read any of the languages historical sources are written in, with a bit of an agenda, skimming through primary research papers looking for interesting claims that seem to support their position and then pasting their own interpretation of those uncritically into a book with some additional interpretive speculation, it's easy to drift away from what is supportable. Many Wikipedia articles have similar kinds of problems. –jacobolus (t) 04:56, 22 April 2026 (UTC)

I have been working on a draft to fix various problems with our numeral-system articles, including reliance upon dodgy sources. Stepwise Continuous Dysfunction (talk) 22:45, 23 April 2026 (UTC)

I'm still mucking about with that draft; suggestions welcome. Stepwise Continuous Dysfunction (talk) 01:36, 29 April 2026 (UTC)

Srinivasa or Srinivas?

As far as I know, Srinivasa Ramanujan firstname is way more common rather than Srinivas Ramanujan, which is used today. Dedhert.Jr (talk) 12:35, 26 April 2026 (UTC)

I think "Srinivas" matches the native pronunciation better so I get the motivation. But his name is spelled with a trailing "a" in so many sources that we probably need a strong secondary source to justify using "Srinivas" abandeali (talk) 12:48, 26 April 2026 (UTC)

It's a regional variation. I suppose a reasonable analogue would be 'Geoffrey' vs 'Jeffrey'. 'Srinivasa' would be the more common version where he was from, and as far as I know most English language sources use 'Srinivasa'. MrOllie (talk) 12:52, 26 April 2026 (UTC)

I've moved the article back to Srinivasa Ramanujan. —Kusma (talk) 13:11, 26 April 2026 (UTC)

Offhand, I don't recall reading any source that used "Srinivas" rather than "Srinivasa". Stepwise Continuous Dysfunction (talk) 01:37, 29 April 2026 (UTC)