Wikipedia talk:WikiProject Mathematics/Archive/2020/Oct

Discussion for improving the implementation of Infobox mathematical statement at Fermat's Last Theorem
There is a new discussion at Talk:Fermat's Last Theorem on improving the instance of Infobox mathematical statement that is used at Fermat's Last Theorem. Any input is appreciated! — MarkH21talk 23:20, 4 October 2020 (UTC)

Requested move notification
This is to notify members of this Wikiprojects that a likely controversial move request of Algebraic character to Formal character is in progress. Your input will be appreciated. Cheers Megan☺️   Talk to the monster  18:02, 8 October 2020 (UTC)

Van Eck's sequence
The page Van Eck's sequence was proposed for deletion and then de-prod'ed. The sources offered on the Talk page don't look all that great to me: a scatterplot from the OEIS, a StackExchange thread, MathWorks, etc. XOR&#39;easter (talk) 18:42, 15 October 2020 (UTC)


 * I had this on my watchlist, but missed the de-PROD. I have nominated it at AfD: see Articles for deletion/Van Eck's sequence.  –Deacon Vorbis (carbon &bull; videos) 20:21, 15 October 2020 (UTC)

Latex on section headings
MOS:MATH currently tells us not to use Latex on section headings, "as LaTeX markup does not appear in the table of contents". However, as the following dummy subsections show (see the TOC of this talk page), Latex is rendered correctly on the TOC, at least for me.

Equal or unequal sample sizes, similar variances $$\left( \frac{1}{2} < \frac{s_{X_1}}{s_{X_2}} < 2\right)$$
Am I missing something?  Walwal20  talk ▾ contribs 01:27, 9 October 2020 (UTC)


 * (I changed Latex to HTML on t-test anyway, since Latex screwed up the vertical line spacing on TOC.)  Walwal20  talk ▾ contribs 01:27, 9 October 2020 (UTC)
 * I'm looking forward to seeing the ToC on Tetration ;) - Astrophobe  (talk) 02:42, 9 October 2020 (UTC)
 * I would not want that last to show up in any TOC of interest. --Izno (talk) 04:04, 9 October 2020 (UTC)
 * I disable TOCs by default, but I still think that to the extent possible section names should be chosen to avoid needing formulas in them. They're going to look ugly in the section header itself no matter how they're formatted. —David Eppstein (talk) 05:34, 9 October 2020 (UTC)
 * It seems that the issue of latex (and wikilinks) in section headings has been fixed. In fact, there are 3 points: 1/ rendering in the ToC; 2/ link form the Toc to the correct section; 3/ link from an arrow in the watchlist to the correct section. I edit this post as belonging to the last above subsection for testing the third point. D.Lazard (talk) 09:58, 9 October 2020 (UTC)
 * It appears that the above 3/ does not work correctly with latex (it works with wikilinks). So, at least in this talk page, latex should be avoided in section headings. D.Lazard (talk) 10:10, 9 October 2020 (UTC)
 * These may work in desktop browsers, but do they work for mobile? We have recently had a discussion about problems with rendering latex formula on different mobile browsers, and there is a phab ticket. Until we can ensure these work for all users on all devices we should keep the MOS unchanged.--Salix alba (talk): 11:08, 9 October 2020 (UTC)
 * Well, we could remove false statements from MOS without changing the advice given. --JBL (talk) 11:11, 9 October 2020 (UTC)
 * , point 3 doesn't work for HTML either. I made a dummy edit to test it. Point 2 works for both cases, but it bothers that Latex cause illegible anchors (#Equal_or_unequal_sample_sizes,_similar_variances_%7F'"`UNIQ--postMath-00000009-QINU`"'%7F) whereas HTML yields a nicer one (#Equal_or_unequal_sample_sizes,_similar_variances_(1/2_<_sX1/sX2_<_2)).  Walwal20  talk ▾ contribs 11:53, 9 October 2020 (UTC)
 * In the absence of new feedback here, I took the liberty to boldly change the wording in MOS:MATH without changing the original advice, as suggested by above. The MOS now reads: except for section headings, which should use HTML only, as LaTeX markup might cause uneven spacing in the table of contents, as well as the appearance of illegible anchor links to sections. I do agree with  that HTML should also be discouraged, but the discussion so far does not raise sufficient consensus on this.  Walwal20  talk ▾ contribs 10:01, 17 October 2020 (UTC)

UNIQ code instead of math rendering
Can someone who know about math rendering please take a look at the "'"`UNIQ--postMath-00000001-QINU`"'. The group '"`UNIQ--postMath-00000002-QINU`"' " code in Circle of fifths? Thanks. – Jonesey95 (talk) 15:23, 21 October 2020 (UTC)
 * There was some weird conflict with the  being used. Removing them fixed the issue...they even had an odd "scores are temporarily disabled" warning on the rendered page.  Probably an issue for phab I guess? You know a lot more about this stuff I think. –Deacon Vorbis (carbon &bull; videos) 15:46, 21 October 2020 (UTC)
 * T257066 seems to be related to the scores being disabled, but I don't see any mention of conflicts with math rendering. –Deacon Vorbis (carbon &bull; videos) 16:01, 21 October 2020 (UTC)
 * That is a strange interaction; I think you did the reasonable thing by commenting out the score sections. I added a note to the phab ticket. Thanks for looking at this. – Jonesey95 (talk) 16:15, 21 October 2020 (UTC)

Erdős–Bacon number
Editors are invited to weigh in here on what kind of sourcing should be appropriate for an Erdős–Bacon number. --JBL (talk) 19:22, 23 October 2020 (UTC)

Yau–Tian–Donaldson vandalism on K-stability page
Can I please get some input in the K-stability talk page in reference to the controversy about the resolution of the Yau–Tian–Donaldson conjecture. This is fairly esoteric stuff, so I'm not sure what technical input to expect, but it is a topic of some contension within the complex geometry community and therefore provokes a lot of edits changing credit around (usually from people in Tian Gangs outer circle who attribute equal/all of the credit for the proof of the conjecture to him). Matters are slightly complicated by the fact that the main rebuttal to Tian's claims of a proof are by Chen-Donaldson-Sun themselves here, which makes it seem like a he-said-she-said situation. Just to summarise for those unfamiliar, the substance of the argument is essentially that Tian put up a paper just days after CDS's paper with several key arguments essentially exactly the same as in CDS, and immediately claimed credit for the proof. The Veblen prize in mathematics was awarded to CDS for their proof, with no reference to Tian, and (and I can only speak informally on this rather than provide written sources) the community outside of Tian's inner circle is fairly decided that the credit goes to CDS.

The user in question (I'm not sure if its acceptable to comment on such things, but their IP links to the University of Utah whose maths department has one person in complex geometry who is a postdoc of Tian's) edited the page to remove all credit to CDS (a clearly ridiculous claim that not even Tian himself supports). I don't think it is accurate to simply give equal credit to Tian and CDS without having a lengthy discussion of the controversy, but given the highly technical nature of the contension and the fact that the main rebuttal is from some of the authors themselves, it makes it a bit difficult to accurately and faithfully write up. Any input would be appreciated.Tazerenix (talk) 11:43, 7 October 2020 (UTC)
 * If I understand well, there are WP:secondary sources that attribute the proof of the conjecture to Chen-Donaldson-Sun (at least Veblen Prize) while no independent source attributes the result to Tian. This suffices to revert the attribution change as WP:OR. However, as the controversy is notable, it seems worth to mention Tian's claim in a footnote. Also, it seems worh to mention Veblen prize to support (source) attribution. D.Lazard (talk) 14:06, 7 October 2020 (UTC)
 * Tian’s paper is very widely cited, on the same level as Chen-Donaldson-Sun’s. So I believe it should be mentioned. I addressed this in one way on Tian Gang‘s page.Gumshoe2 (talk) 16:37, 7 October 2020 (UTC)
 * I've added Tian's credit and added links both to CDS's criticism and Tian's rebuttal. Hopefully this resolves the issue.Tazerenix (talk) 14:39, 9 October 2020 (UTC)
 * Your phrasing takes the point of view of Tian, using words that imply that the CDS accusation is dubious ("they have alleged"; "alleged" carries a connotation that the allegation might not be true) while asserting that Tian's response is the more correct version of the story ("Tian has rebutted"; "rebutted" means "definitively proved incorrect"). After an edit by User:Gumshoe2 it also states, in Wikipedia's voice rather than as a disputed claim, that Tian's proof is independent of the others. Is that an accurate and neutral description of this controversy? —David Eppstein (talk) 17:19, 9 October 2020 (UTC)
 * Rebut means "claim or prove that (evidence or an accusation) is false", so I think it is a neutral word to use. I've removed the word "independently". Gumshoe2 (talk) 17:23, 9 October 2020 (UTC)
 * Just to be clear, I think it is best to take the perspective that there are papers by Chen-Donaldson-Sun and by Tian which claim to prove the conjecture, and that there is unresolved dispute over Tian's. I think "allege" and "rebut" are neutral words for that purpose but I don't mind anyone else's edit to the same effect. Gumshoe2 (talk) 17:28, 9 October 2020 (UTC)
 * I had actually thought I was being too harsh on Tian in my wording! I was trying to write it impartially, so if the wording needs adjusting I would encourage someone to improve it! This of course is a matter better discussed on the talk page. I suppose I should remark that Tian's proof is very much not independent mathematically (the details are almost identical in most places, hence the controversy) but I think after Gumshoe2's edits it comes across neutrally. That is to say, the baseline assumption is that Tian's effort to find the proof was independent, and this is what is disputed by CDS (whether or not the details are mathematically independent). I think this is reflected fairly neutrally in the text now. Tazerenix (talk) 18:01, 9 October 2020 (UTC)
 * "Disputed", as you just used in your comment, is sufficiently neutral wording. Unlike "rebutted" it does not carry the connotation that the counterargument is convincing to all. —David Eppstein (talk) 18:19, 9 October 2020 (UTC)
 * Thank you for your input and edits!Tazerenix (talk) 18:28, 9 October 2020 (UTC)
 * I don't think "rebut" is quite as strong as says.  Refute means "prove false"; one of my peeves is when people use it to mean "deny" or "contradict".  But "rebut" is not quite as strong as "refute".  I would take "rebut" to mean something like "present a reasoned argument intended to refute". --Trovatore (talk) 00:17, 24 October 2020 (UTC)

Barnstar


Hello everyone! I created a barnstar for the Mathematics WikiProject, which currently lives at User:AviationFreak/MathStar and looks like this:

I'm posting here to see if people more associated with the project would like this addition - If so, I'll add it to the project page. AviationFreak 💬 00:39, 5 October 2020 (UTC)
 * Looks fine to me. I might have it say "contributions" instead of "contribs"; I don't see why the word benefits from being shortened here. XOR&#39;easter (talk) 00:50, 8 October 2020 (UTC)
 * The text is customizable; I've just used the message shown here to demonstrate this functionality. AviationFreak 💬 01:28, 8 October 2020 (UTC)
 * Ah, OK, that makes sense. XOR&#39;easter (talk) 17:22, 8 October 2020 (UTC)
 * I believe most barnstars are five pointed. Paul August &#9742; 17:41, 8 October 2020 (UTC)
 * I was attempting to do something math-related in making this barnstar a Koch snowflake. I believe six is the usual number of points for a Koch snowflake, but if a five-pointed one exists please let me know. Thanks! AviationFreak 💬 18:45, 8 October 2020 (UTC)
 * For what it's worth, I think the Koch snowflake here is a nifty idea. If someone really wants a 5-pointed star, another possiblity might be some tweaking of an appropriate Newton fractal (see thumbnail for example). –Deacon Vorbis (carbon &bull; videos) 19:10, 8 October 2020 (UTC)
 * I received a barnstar using this exact Koch snowflake image in 2017, so it is already in informal use, at least. Another non-five-pointed star that I've seen used as a barnstar is File:Small stellated dodecahedron.png (although that one does contain numerous five-pointed stars within it). —David Eppstein (talk) 19:17, 8 October 2020 (UTC)
 * The small stellated dodecahedron is my favorite of the suggestions so far; it's a bit more visually dramatic than the Koch snowflake, and it depends less on color perception than the Newton fractal. XOR&#39;easter (talk) 18:16, 9 October 2020 (UTC)
 * I hadn't considered color perception - The dodecahedron would probably be a better fit, unless users here really prefer the "flat" barnstar look as opposed to something more 3D-y. AviationFreak 💬 01:57, 12 October 2020 (UTC)
 * As someone who doesn't really care all that much, I prefer the fractal. The dodecahdron's shading makes it fairly complex to parse visually. If fractals are deemed a nope, then maybe a Petersen graph like File:Petersen1 tiny.svg. &#32; Headbomb {t · c · p · b} 03:02, 12 October 2020 (UTC)
 * I think the snowflake one would be a nice addition. I also think it would be nice to have an official mathematics barnstar, as the currently used "E=mc² Barnstar" has a much more physics-feel than math.  Walwal20  talk ▾ contribs

We've had some discussion here; If anyone uninvolved in the discussion wants to add it to the WikiProject page after having read the discussion, I say go ahead. I would ask that you move my userspace page to a page in this Project's namespace. AviationFreak 💬 01:47, 16 October 2020 (UTC)

FYI, there already is one for "mathematics and science" at WP:BARNSTAR. And if you don't propose this new, more specific variant at Wikipedia talk:WikiProject Wikipedia Awards, you might get revert-warring if you try to add it to WP:BARNSTAR. (No, I don't approve of that fact, as a WP:NOT problem, but I've directly run into it before.)  — SMcCandlish ☏ ¢ 😼  05:16, 19 October 2020 (UTC)
 * I had originally only thought of this as a star for this project, but I do think (as another commenter pointed out) it could be used in some cases instead of the "E=mc²" star, which currently covers a pretty broad range of topics. Nominating at WT:WikiProject Wikipedia Awards. AviationFreak 💬 15:02, 19 October 2020 (UTC)

Per request, I came up with this:

– Jerm (talk) 00:15, 21 October 2020 (UTC)
 * Does this meet satisfactory? I used File:Nuvola apps edu mathematics-p.svg from the project banner. Jerm (talk) 19:17, 21 October 2020 (UTC)


 * If we are talking about an official barnstar to be listed at WP:BARNSTAR, I'd expect something more than &radic;x. I don't think I can beat the shininess of the Nuvola apps icon, but this is what I got (see logarithmic integral):
 * I think the snowflake one is heading on the right direction. Any thoughts?  Walwal20  talk ▾ contribs 03:26, 23 October 2020 (UTC)
 * The snowflake is actually heading to the wrong direction if you want an official barnstar at WP:BARN. Barnstars must go according to WP:B2G, but there are no rules for WikiProjects to have their own collection of awards. Jerm (talk) 03:39, 23 October 2020 (UTC)
 * I'm not quite sure, but I believe the tropical cyclone has 6 points:
 * The snowflake is actually heading to the wrong direction if you want an official barnstar at WP:BARN. Barnstars must go according to WP:B2G, but there are no rules for WikiProjects to have their own collection of awards. Jerm (talk) 03:39, 23 October 2020 (UTC)
 * I'm not quite sure, but I believe the tropical cyclone has 6 points:


 * Also, many barnstars go against the clipart size recommendations too.
 * I think I can circumvent the main problem by inscribing a barnstar inside the Koch snowflake. If it is almost transparent, it might even look great. I'll leave that to tomorrow tho.  Walwal20  talk ▾ contribs 03:54, 23 October 2020 (UTC)
 * The Tropical Cyclone Barnstar has five tips. The lightning is clip art, and the majority of barnstars do follow the guidline. Any barnstar @WP:BARN that is on the 1.0 row are older originals approved years ago. Jerm (talk) 04:22, 23 October 2020 (UTC)
 * Ouch. I'm blind and stupid for misinterpreting it so badly. I'll see what I can do to make it fit the guidelines.  Walwal20  talk ▾ contribs 05:02, 23 October 2020 (UTC)
 * I'll give leniency since some of the new barnstars have clip art behind the actual barnstar like File:Nuclear Barnstar Hires.png but not the entire background. Even the Tropical Cyclone Barnstar is not exactly a "normal" barnstar either. Just do your best really. Jerm (talk) 05:22, 23 October 2020 (UTC)

Some more possibilities for five-pointed thingies that are at least vaguely mathematical and not just "ooh it's a fractal": —David Eppstein (talk) 06:06, 23 October 2020 (UTC)
 * The Perles configuration
 * The recognition sign of the Pythagoreans
 * An impossible Penrose pentagram

I looked up this alleged "guideline" and as far as I can tell you are completely free to ignore it utterly, a great many barnstars do ignore it utterly, and that's what I recommend. I think your original offering at the top of this section is the best one. Who cares if it has sixfold instead of fivefold symmetry? It evokes the barnstar, it's mathematical, and it has a pleasing simplicity that the others lack. Superimposing a random formula on top of it, in particular, is in my estimation not an improvement. In short, nice work! I !vote for your original effort. --Trovatore (talk) 07:14, 23 October 2020 (UTC)
 * Out of the options given so far, the original proposed barnstar looks the cleanest and least jarring in terms of color & readability. I don’t see much in WP:B2G for guidance (but it does seem to suggest that one has to use File:Original Barnstar Hires.png?). — MarkH21talk 07:45, 23 October 2020 (UTC)
 * & WP:B2G has been a long-standing guideline for many years. It literally tells you how to make a barnstar and what file to use, and you’re correct MarkH21, you have to use File:Original Barnstar Hires.png. If you see anything that doesn’t use this file at WP:BARN, you are viewing the 1.0 row which are original awards most likely created before the introduction of the guideline. Some were made after but were still put on the 1.0 row. If members choose the snowflake more than anything else, it will be put on WP:BARN but only on the 1.0 row and on a list for remastering until it meets 2.0/WP:B2G. That doesn’t mean though you can’t use it. It just means it’s the original and possibly outdated. I already made a barnstar that meets the guideline, so my version would be put on the 2.0 row next to the snowflake. That would be the outcome if members of this project choose the snowflake, it will be next to a 2.0 barnstar. Jerm (talk) 13:43, 23 October 2020 (UTC)
 * Frankly, WP:B2G doesn't look like it has any consensus behind it and is little more than one user's recommendation for how barnstars "ought to be" made. After looking at the talk page of the guideline, it looks like a couple other users share my thinking here. In my opinion, barnstar design should be more of an art than a science, with guidelines that reflect that. We don't need specific guidelines telling us which file we must use as our base image - That's what community consensus is for. It seems like a few other users here prefer the original Koch Snowflake design, so I don't think it should be thrown out due to the fact that it uses the "wrong" image. Personally, I would be happy to support any of the barnstar designs suggested by David Eppstein - I think all of these designs would work better than a generic "math thing" superimposed on a clipart barnstar. Mathematics is unique and often beautiful, and I think a barnstar should reflect that. AviationFreak 💬 14:42, 23 October 2020 (UTC)
 * That has been a long-standing guideline. Just because you don't like it doesn't give you the right to surpass a guideline for which WikiProject Wikipedia Awards follows. Jerm (talk) 14:57, 23 October 2020 (UTC)
 * I'd like to point out that I'm only disagreeing with one point of the guideline - I don't think every barnstar should have to use the same image. In most topics listed at WP:BARN, there isn't a very snazzy star-shaped symbol to represent the topic. For instance, Law Enforcement, Christianity, and Football/Soccer don't really have something star-shaped to represent them. In most topics, this is the case. In some cases however, like Mathematics or Tropical Cyclones, a snazzy star-shaped symbol is available for use. In those cases, it should be used. Even if we agree that B2G should be/is an official guideline, I think this still falls under WP:IAR. AviationFreak 💬 15:07, 23 October 2020 (UTC)
 * The original Tropical Cyclone was created in 2006. I was not around when that happened and neither was the guideline, and a barnstar is literally File:Original Barnstar Hires.png. I said the snowflake can be added in the 1.0 row, but there also has to be a 2.0/WP:B2G version. Jerm (talk) 15:23, 23 October 2020 (UTC)
 * Here is a quick sample I made with the snowflake:

— Jerm (talk) 15:53, 23 October 2020 (UTC)


 * would it be possible to make the snowflake be in front of the barnstar, maybe with just a little transparency to barely make the barnstar visible? (in your barnstar, it is already in front, right? Just increase the opacity of the snowflake internals.) That could make a very fine barnstar, and would be much better than The Winnowing Fan Barnstar in terms of not hiding the File:Original Barnstar Hires.png completely:


 * I'd also like to thank you for your efforts in designing a new barnstar!  Walwal20  talk ▾ contribs 18:51, 23 October 2020 (UTC)
 * The Winnowing Fan Barnstar is actually on the "need to be remastered list." As you can tell, there's not much of a barnstar to view, but I will come up with another sample. Jerm (talk) 19:04, 23 October 2020 (UTC)
 * Actually, I've been making different styles, but they all look terrible. I don't think I can do any better with the snowflake, sorry about that. Since you introduced the snowflake. Is Walwal's version File:Mathematics barnstar2.png good enough for you? Jerm (talk) 20:46, 23 October 2020 (UTC)
 * I think Walwal's star looks great! AviationFreak 💬 20:53, 23 October 2020 (UTC)
 * I've added it to WP:BARN. Jerm (talk) 21:12, 23 October 2020 (UTC)
 * I don't care for the unmotivated $$\int\frac{dx}{\ln x}$$ superimposed on it. What's that even supposed to be about? --Trovatore (talk) 23:52, 23 October 2020 (UTC)
 * Judging from this edit, User:Jerm is ignoring both this criticism of its meaninglessness and the ongoing discussion of better alternatives, and pushing forward with this ugly choice because it looks sort of mathy. —David Eppstein (talk) 00:36, 24 October 2020 (UTC)
 * No, I didn't pick the snowflake, participants is this discussion did. As for the math equation, that's a decision for this project to decide. If you're wondering why I just suddenly decided to pick the snowflake despite my opposition, it's because I don't need to make a remastered version that meets WP:B2G when I already made a barnstar that meets it hence the green barnstar above. The snowflake has been added as the original version because this project has chosen it. Jerm (talk) 00:51, 24 October 2020 (UTC)
 * Btw, If you want to take the snowflake down from the main page, go ahead, I'm not stopping you. I did that out of courtesy. I've already done my part. If you want me to take the snowflake down from the main page, just ask and I'll do it. If you don't like the snowflake, then you should be addressing the person who made it. Jerm (talk) 01:04, 24 October 2020 (UTC)
 * Don't worry, I took it down. I'm done with this. It seems no one here can't agree on anything. This person wants this, this person wants that, this person likes it, this person doesn't. No, I presented a guideline for which people must follow to make a barnstar. It's literally a "How to" guide and even tells you what file to use, but no, no body wants to follow a long-standing guideline. In response, everyone is suggesting to just ignore it to get what they want. Those kinds of responses I'd expect only from newly registered editors who ignore policy and guidelines, and everyone here should already know what happens to users who continue to ignore policy and guidelines. I'm doing the best I can, but participants are so divided amongst themselves, it's almost impossible to determine consensus. The only thing that was clear enough was the snowflake, but now someone doesn't like the equation or the snowflake itself. I didn't even make the snowflake, it was Walwal20. The green barnstar above, that's the first thing I introduced here. I used the image file from this project banner because a image file from the project banner is the best representation of the topic for which a WikiProject covers. Clearly I was wrong though, but what's even more clear, is the amount of rudeness I have received for my efforts. Jerm (talk) 02:10, 24 October 2020 (UTC)

Hi, thanks for the efforts. I think it doesn't change the fact that there is a barnstar for mathematics in WP:BARN, which is progress. Also, sorry for the rudeness of our fellow mathematicians. I believe it is all a misunderstanding though, because most people supported the snowflake-only barnstar, not the one with the equation. I took the liberty of making all the changes to reflect this "better" consensus. It has the support of David Eppstein, Deacon Vorbis, AviationFreak, MarkH21 and Trovatore. And since it is placed as a 1.0 (not a 2.0 one), I think Jerm is also fine with it not having 5 tips. Think we can settle with this, right?  Walwal20  talk ▾ contribs 03:05, 24 October 2020 (UTC)
 * As for the $$\int\frac{1}{\ln x} dx$$, it really was a sort of random choice. If anyone has a better suggestion, I can implement it. I had also thought of $$e^{2\pi i} = 1$$, but it would remount to the $$E=mc^2$$ barnstar...  Walwal20  talk ▾ contribs 03:11, 24 October 2020 (UTC)
 * Thank you and the snowflake is fine now as is anything else for the 1.0 version because a 2.0/WP:B2G version doesn't have to be made when I already made one via File:Mathematics Barnstar.png. And my apologies as well. This discussion wouldn't have dragged on if I just said something a lot sooner. Jerm (talk) 03:16, 24 October 2020 (UTC)

We’re still talking about this? The original is the nicest. The right margin is oddly narrow when there’s no text, but maybe it corrects when a comment is added? —JBL (talk) 13:15, 24 October 2020 (UTC)

Exceptionally young IMO medallists
I have opened a new discussion at Talk:List of International Mathematical Olympiad participants where we have an entire section of Exceptionally young medallists with their date of birth sourced to Wikidata and as such possible violation of our WP:OR policy. Please contribute to this discussion. Solomon7968 05:39, 25 October 2020 (UTC)

Improving rendering of radical symbol
Apparently intended as an inline alternative to , radic uses √ and overline to render square roots, etc. like this: √7, $1⁄2$. At least in my web browser, the horizontal and diagonal lines don't actually connect, which to me looks pretty horrible.

Using  renders the same expressions like this: $$\sqrt{7}$$, $$\sqrt[3]{4}$$. This should look the same in all browsers.

Deacon Vorbis points out at Template talk:Radic that  syntax currently doesn't work in the Media Viewer extension (the output of which is what you see on English Wikipedia if you view an image on a mobile device) so at least in the short term that method still needs to be used in image captions. But for the majority of uses, which appear in general article text, I would like to replace the instances of radic (of which I see about 1300 in the September 1 database dump) and √ + overline (of which I see about 100) with  markup (of which I see about 67,000 instances using \sqrt).

Deacon Vorbis thinks this would be a waste of time, but I'm not asking anyone else to help. What do people here think? Are there any other circumstances where this change should be avoided? Any better alternatives? -- Beland (talk) 17:09, 22 September 2020 (UTC)
 * I think radic looks bad enough that it should always be replaced by &lt;math&gt;. More, I think that in articles that need radicals or other mathematical expressions too complicated to render nicely using templates, all mathematics should be formatted by &lt;math&gt;, because otherwise the inconsistencies between formatting of one type of mathematical expression and another using the same variable names but in a different font are worse than the problems caused by Wikipedia's poor implementation of &lt;math&gt;. —David Eppstein (talk) 17:22, 22 September 2020 (UTC)
 * I 100% agree. We should replace the √ + overline with just √ or with . Whatever the replacement is, we should get rid of √ + overline which looks awful and can even be confusing (e.g. a reader could wonder whether $1⁄s_{X_{1}}|s_{X_{2}}|undefined$ refers to a square root of $a - bi$). — MarkH21talk 17:32, 22 September 2020 (UTC)
 * Eh, I said a hell of a lot more than that it would be a waste of time, and oversimplifying my rationale like that is kind of dishonest. There's just no good reason to kill off  – a slight aesthetic shortcoming isn't enough.  Basic square roots are fine in running text, as are any basic expressions, and it's a reasonable option to have for editors, and it's extremely widely used.  And overall dissatisfaction with  vs.  isn't what this is about.  It's here, and it's widely used, and this isn't about that.  It's about .  –Deacon Vorbis (carbon &bull; videos) 17:42, 22 September 2020 (UTC)
 * I did not intend to misrepresent your position; I was just trying to sum up a longer conversation and my apologies if that is not what you meant. I did point you to this thread so you could jump in and speak for yourself, and linked to the other conversation so readers could get more detail. -- Beland (talk) 17:59, 22 September 2020 (UTC)

FTR, for ease of reference I documented what seems to be the consensus position on the √ issue at MOS:RADICAL. I agree with the idea of fully converting articles to  markup for consistency where at least some can't be rendered properly without it, and I've already been doing that while doing unrelated cleanup. If no one objects to this first MOS addition in the next day or two, I'll see if there's any objection to adding that to the MOS as well. -- Beland (talk) 00:56, 24 September 2020 (UTC)
 * This is complete nonsense. It conflates several issues, and you're ignoring the standing ability of editors to use text-style math rendering in violation of the spirit of MOS:STYLERET.  Wholesale conversion to <math ></math> isn't appropriate, and just finding that a couple people agree with you isn't enough for a change like this.  This is not productive.  –Deacon Vorbis (carbon &bull; videos) 01:02, 24 September 2020 (UTC)
 * I see you reverted the addition using a minced vulgarity as an edit summary. I don't think this was appropriate, both in terms of civility and because so far editors seem to prefer that solution 3 to 1. This WikiProject and the Mathematics MOS page are the places I can think of that are most likely to find editors interested in these issues. Is there some other forum you think should be alerted to this proposal to test for consensus? -- Beland (talk) 01:13, 24 September 2020 (UTC)
 * Really? You're going to complain over "BS"? Really? The fact is, you should just drop this.  Trying to steamroll longstanding practice by 3 people is not appropriate.  This isn't a problem that needs fixing.  And I don't have the energy to devote to arguing over this constantly.  I'm doing other things here.  You haven't even remotely fucking listened to a word I've said in earlier discussions, just plowing ahead with your fingers in your ears, and it's tiring. –Deacon Vorbis (carbon &bull; videos) 01:20, 24 September 2020 (UTC)
 * As far as I know, Manual of Style/Mathematics is under control of this wikiproject, so I don't see any other better place to find consensus either.
 * That aside, the discussion has not been online long enough to establish consensus, I'd say, .  Walwal20  talk ▾ contribs 01:24, 24 September 2020 (UTC)
 * Let me also add my support to the idea of discontinuing usage of √  Walwal20  talk ▾ contribs 01:24, 24 September 2020 (UTC)
 * It seemed to be snowballing, but shall we give it a week and see if anyone else weighs in? -- Beland (talk) 01:32, 24 September 2020 (UTC)
 * You should review WP:CONLEVEL. To wit, no, the manual of style is the community's, not this WikiProject's. (It happens to be the case that editors of this WikiProject are the most likely to care about the guideline in question, but this set of editors is not the entire set of editors who care about the guideline, and accordingly do not get to control what that guideline says.) --Izno (talk) 02:16, 24 September 2020 (UTC)
 * I'm aware of WP:LOCALCONSENSUS. "in control" was a wrong way to put it. What I meant is that if we get consensus here in the wikiproject, we can boldly edit the MOS/Mathematics; and most probably no one would revert it on the basis of WP:BRD.  Walwal20  talk ▾ contribs 02:21, 24 September 2020 (UTC)

By the way, I did not say that radic has to be replaced by <math ></math>. There may be other alternatives, like a bare √ without an overline. Whatever the case, you can open a Request for Comment (probably at Wikipedia talk:Manual of Style/Mathematics with a notification here) to establish broader formal consensus. — MarkH21talk 01:35, 24 September 2020 (UTC)
 * Ah, thanks for the clarification. I interpreted that comment as applying to no-argument uses like "the radical symbol (√) is..." but it sounds like you also mean to include with-argument expressions like "√2 is an irrational number because...". I'll add a question about that option, and hereby invite editors to point out any other alternatives they like. Just to avoid smearing comments across three separate pages, I'll start the RFC in a subsection below and point to it from the Mathematics MOS talk page. -- Beland (talk) 05:38, 24 September 2020 (UTC)

I agree that radic's use should be strongly discouraged, for already-voiced reasons. --Izno (talk) 02:17, 24 September 2020 (UTC)

MediaViewer and &lt;math&gt;
This discussion has highlights the incompatibility of MediaViewer and. This fails even in desktop browsers. I've created a phabricator task for this. I imagine it will take a long time to fix.

p.s. A couple of small math rendering bugs have been recently fixed, "Rendering of \oinit very dense" is fixed and : "Incorrect spacing for \mathbin and \mathrel", is waiting for the fix to make it through code review. I think some of the backend problems are now fixed which should make simple bugs quicker to fix. --Salix alba (talk): 18:45, 22 September 2020 (UTC)
 * Ah dear, I'd just filed . -- Beland (talk) 17:54, 23 September 2020 (UTC)
 * No worries, the bugs have been merged. Great minds think alike. I could not replicate your bug but found one which failed. What mobile/browser were you using? --Salix alba (talk): 21:00, 23 September 2020 (UTC)
 * I was using Chrome on Android. Interestingly, looking at your example I do see that the equation is missing on Linux Firefox, rather than generating a syntax error. On Android Chrome, though, I don't see a caption at all for your example. 8/ -- Beland (talk) 01:03, 24 September 2020 (UTC)

Radical RFC comments
Request for comment: Should inline √ expressions be rendered with <math ></math> like $$\sqrt[3]{4}$$ where technically possible instead of with radic like $\sqrt{3|4}$ (which uses √+overline)? -- Beland (talk) 05:38, 24 September 2020 (UTC)

Proposed changes to the section for Manual of Style/Mathematics, concerning "Radical symbol":

The radical symbol Unicode character (√) can be used when only the symbol itself is needed.

When part of a larger mathematical expression, radic is the best way to write such expressions in HTML, but the result is unattractive due to the hole between the overline and the radical symbol in many web browsers:

This method should be avoided whenever technically possible. Instead, use <math ></math> tags and \sqrt{}, even if inline. For example:
 * $$\sqrt{9}, \sqrt[3]{27}$$

Because of Mediawiki bug, <math ></math> markup is incompatible with the Media Viewer (used for full-screen image viewing on mobile devices), so until that is fixed, the radic method should be used in image captions.

Further comments by the proposer.

This proposed text does not mention the "bare Unicode character + no overline" option, like "√2" or perhaps "√(a - b)", but this could be added if editors support it.

(Note some editors have already commented at the beginning of this section.)


 * Considering the "bare Unicode character + no overline" option...something simple like "√2" is intuitive and clean, and I do see web pages using Unicode in this way, which is probably how it was intended. It bothers me a little that there's no vinculum, but aesthetically it's less bothersome than one with a broken line. In simple situations like "√2" it's not needed for clarity, but in complex situations like "√a - b" it would be ambiguous what's being rooted. Something like "√(a - b)" would resolve that ambiguity, but I would lean toward using <math ></math> in these situations. Certainly I'd use <math ></math> for consistent appearance if it had to be used somewhere else in the article. I wouldn't object if other editors want to keep this option, but if it were entirely up to me, I'd probably just use <math ></math> in all cases where there's an argument, to minimize the number of conventions in use and to improve cross-article consistency of appearance. For the record, I see "√" followed by a digit (0-9) in the September 1 database dump about 970 times (slightly less than the number of uses of radic, and "√(" about 300 times. -- Beland (talk) 05:38, 24 September 2020 (UTC)

Please place your comments below.
 * Support using &lt;math&gt; for all radical symbols, except possibly when talking about the symbol itself or in special circumstances where for technical reasons &lt;math&gt; doesn't work (the only circumstances like this that I can think of offhand are when you want to make a wikilink on the formula like &radic;2 or in a reference with both a formula in a title and a link on the title). —David Eppstein (talk) 06:40, 24 September 2020 (UTC)
 * Support, though I think the use of (√ + no overline) should be encouraged too, otherwise people who write mathematics in HTML will always have to use Latex for rendering radicals, which seems to break the so-important consistency per MOS:MATH.  Walwal20  talk ▾ contribs 02:15, 25 September 2020 (UTC)
 * hope you don't mind, but I made some style changes to the request for comment, to make it easier to find stuff around. Also humbly inviting, and  to cast their votes officially here, as they were present in the discussion earlier. Best,  Walwal20  talk ▾ contribs 01:54, 25 September 2020 (UTC)
 * Sure, thanks for that. -- Beland (talk) 17:41, 25 September 2020 (UTC)


 * Support - the template radic seems to be a relic of the time when browsers couldn't render LaTeX properly, and had to generate PNG images for that. Since support is now universal, there's no reason to to refrain from a proper <math ></math>. Tercer (talk) 10:52, 25 September 2020 (UTC)
 * Oppose the radic alternative gives something that can be searched and copied, unlike the math template example. Graeme Bartlett (talk) 11:21, 25 September 2020 (UTC)
 * That's a good point, though I wonder how often that would just work and how often the user would need to transcribe the formula into some other syntax for whatever math tool they are using locally. (Though a working copy-paste would still help in either case.) In the long term, it might be possible to fix this downside by technical means; to get the ball rolling on that I just filed . -- Beland (talk) 17:41, 25 September 2020 (UTC)
 * Please note that copying already works; it gives you valid LaTeX input. Which is what I need anyway, I'm usually copying either from Wikipedia from Wikipedia, or from Wikipedia to a LaTeX document I'm using locally. I'm a bit skeptical about the use case where you would want to copy a formula and have it as anything other than LaTeX. Tercer (talk) 06:49, 26 September 2020 (UTC)
 * Ah, you're right. Highlighting is a bit futzy but is possible if you go a bit further to either side than usual. Does that work for you? Maybe I should close that feature request? -- Beland (talk) 04:00, 28 September 2020 (UTC)
 * Search does work for equations in tags, I've used a bit for finding uses of specific latex commands e.g.  but its probably useless for trying to find a specific equation. For copying the latex of the equation is available in a hidden span in the source code, I've a short script in my User:Salix alba/vector.js which copies the latex equation from math tags when you double click on the equation, it's quite handy. Vanilla MathJax has a right click menu which allows the equations to be copied to the clipboard, as Latex, MathML or if present any annotation text. This seems to have gone from our system. --Salix alba (talk): 17:38, 27 September 2020 (UTC)
 * Per my comment above, support. --Izno (talk) 14:45, 25 September 2020 (UTC)
 * Support: As with my pre-RfC comment, I 100% agree. We should replace the √ + overline with just √ or with $...$. Whatever the replacement is, we should get rid of √ + overline which looks awful and can even be confusing (e.g. a reader could wonder whether √a + bi refers to a square root of a - bi). The proposed MOS change shifts preference to the LaTeX for most purposes but does not explicitly forbid radic and √ for cases when copy-ability is necessary. — MarkH21talk 06:58, 26 September 2020 (UTC)
 * Support<math ></math> is much nicer looking and also more semantically meaningful than overline. Jackmcbarn (talk) 16:46, 27 September 2020 (UTC)
 * Support This is not a radical proposal. Bubba73 You talkin' to me? 04:03, 28 September 2020 (UTC)
 * Strongly oppose For inline mathematics. Do none of you realize you can't copy and paste those characters, they mess up the flow of text. There must be a better option than using rendered PNG files to display inline math. Footlessmouse (talk) 07:12, 10 October 2020 (UTC)
 * As we discovered above, you actually can copy-and-paste the rendering of <math ></math> markup. -- Beland (talk) 15:38, 11 October 2020 (UTC)
 * Which plays better as part of a line of text: $\sqrt{a + bi}$ or $$\sqrt[4]{3}$$? To me they look about equally disruptive to the spacing. I don't think there's a good way of writing exponents in big blocks of texts. - Astrophobe  (talk) 01:56, 12 October 2020 (UTC)
 * Support I appreciate that math mode has downsides, but in my opinion the existing radic solution that cobbles together multiple symbols that visibly do not even line up is just too janky. - Astrophobe  (talk) 01:53, 12 October 2020 (UTC)
 * Support seems to be strong, so I reimplemented the proposed change, and will start fixing articles. -- Beland (talk) 02:41, 18 October 2020 (UTC)
 * Well, I was reverted by User:Deacon Vorbis who said the above results don't represent a consensus, so we'll await a formal closure by someone else. -- Beland (talk) 06:24, 18 October 2020 (UTC)
 * I am happy to close this, unless someone gets there before me. &mdash; Martin (MSGJ · talk) 12:58, 18 October 2020 (UTC)
 * Go for it. --Izno (talk) 13:19, 18 October 2020 (UTC)
 * We prefer simple text for simple expressions, radicals included. This has been common practice, and trying to force use of <math ></math> for this one case is a horrible idea, and there's .  It's one thing if you want to recommend the use, but any large-scale changes away shouldn't be done. –Deacon Vorbis (carbon &bull; videos) 13:25, 18 October 2020 (UTC)
 * The proposal was not for two markup methods from which editors could choose one and then we'd not change back and forth. It was definitely not to retain the status quo. It was to use the <math ></math> markup method wherever technically possible. Your personal opposition to the proposal is noted and understood, but a supermajority of editors commenting on the RFC did not agree with your position. -- Beland (talk) 17:22, 18 October 2020 (UTC)


 * Oppose per Graeme Bartlett (search concerns) and for MOS:ACCESSIBILITY reasons; the  version results in some elements of the results being tiny and hard to read.  — SMcCandlish ☏ ¢ 😼  05:08, 19 October 2020 (UTC)
 * Perhaps you could give some examples of your accessibility concerns, as no one else has mentioned this? For example how does $\sqrt{3|4}$ compare with $$\sqrt[4]{3}$$? &mdash; Martin (MSGJ · talk) 10:31, 21 October 2020 (UTC)
 * For me, the degree (in this case "4") renders at about the same size in both instances, though in a different font. They are smaller than the main text, but that's how the notation works. If the <math ></math> rendering is hard to read, then perhaps we should increase the font size that the rendering engine puts out. There are over 21,000 expressions that use this markup in the October 1, 2020, database dump, and it's not feasible to stop using that method for complicated expressions. We could also advise people who find any part of an article difficult to read to increase the zoom level on their browser (that works for me), though I do try to remove things like CSS that sets the font size at 80% and whatnot for this same reason. -- Beland (talk) 17:56, 21 October 2020 (UTC)
 * Perhaps there are differences in how screen readers interpret each rendering. Does anyone have any info on that? &mdash; Martin (MSGJ · talk) 21:32, 21 October 2020 (UTC)
 * Help:Math says the hidden MathML generated by <math ></math> markup is compatible with screen readers. -- Beland (talk) 22:58, 22 October 2020 (UTC)

Bogdan Suceavă
I can't judge Bogdan Suceavă's notability as a writer, but despite the long section on his mathematical career, it seems to include little that would count as notable by usual wiki standards. Just passing it along in case someone would like to improve it. Gumshoe2 (talk) 03:44, 26 October 2020 (UTC)
 * Perhaphs the most interesting thing is the paper he wrote on Nicole Oresme and development of the concept of curvature. The history of curvature is a subject where we are sadly lacking.--Salix alba (talk): 09:02, 26 October 2020 (UTC)

Radon–Nikodym theorem
I think I'd appreciate some help/advice with the Radon–Nikodym theorem article. I'm wanting to avoid a slow-motion edit-war and seem to have ended up in paralysis.

In August, an unnamed user edited the proof, which meant that when I came to read it (for the first time) shortly afterwards it seemed to me to be invalid. The previous version seemed basically okay, so I reverted the edit, adding an explanation at Talk:Radon–Nikodym theorem. A while later, this was re-reverted anonymously by a different IP address (though quite possibly the same person), with no discussion.

At that point, I decided the best thing I could do was to add some extra detail to the Talk page expanding on my concerns, and to leave the main article untouched in the hope that a third editor might provide a fresh view. That was on 8 October 2020 and in the meantime nothing has happened. I'm not sure where best to go from here, so we end up with a reliable version. Any suggestions or comments would be very welcome. Thanks, NeilOnWiki (talk) 08:45, 23 October 2020 (UTC)
 * I suggest you just revert or edit to what you want. The anon editor may no longer be around. If he is, take it to the talk page of the article and see if you can get consensus. --Bduke (talk) 08:58, 23 October 2020 (UTC)
 * Thanks. I've given that a go, (re-)reverting and adding some motivating comments to the part of the proof that was (I think) wrongly edited. The terse style of mathematical proofs tends to make them read like they were beamed down from outer space, so I hope some commentary may be more generally helpful, too. NeilOnWiki (talk) 21:11, 26 October 2020 (UTC)

Subgroup and other notations
I am rewriting List of mathematical symbols. In the current version and in Subgroup, it is asserted that ≤ and < are "commonly used" for denoting respectively a subgroup and a proper subgroup. I am convinced that some authors used this notation, but I am not sure whether this is sufficiently common for being mentioned. I am unable to test this with a Scholar Google search. Does this meaning of the inequality symbols must be kept, or must it be removed per WP:UNDUE.?

I have similar questions for the use of $$\leqq$$ with a different meaning from $$\leq$$ (for vector inequality), and for the use of $$\ll$$ for absolute continuity in measure theory. D.Lazard (talk) 10:24, 21 October 2020 (UTC)
 * I had a look at some standard abstract algebra references (Lang's Algebra, Pinter, Artin) and they don't seem to use < and ≤ for subgroups, and shockingly, even some more modern references (Aluffi Chapter 0, the stacks project) appear not to use this notation. I find this quite bizarre, as I have found it to be quite common (it has appeared frequently in lectures and courses I have attended for example). Since it doesn't appear to be well represented, I suppose it could be removed from the < and ≤ parts, but I think one then should add it to the ⊆ ⊂ section separately to subset (as these references certainly do use set notation to indicate subgroups in this way). Perhaps one could even put a small note there that < and ≤ are sometimes used.
 * On the other hand, $$\ll$$ is definitely common for absolute continuity of measures (for example it is used in Stein-Shakarchi Real Analysis and Rudin Real and Complex Analysis, two standard measure theory references). I have no comment about $$\leqq$$ for vector inequalities, this doesn't seem to be common.Tazerenix (talk) 12:03, 23 October 2020 (UTC)
 * I have frequently seen ≤ and < as notations for subgroups. It is the standard notation in Abstract Algebra by Dummit and Foote and Group Theory by Scott, for example, and is common enough to be mentioned (in my person experience). — MarkH21talk 19:13, 28 October 2020 (UTC)
 * I can confirm that ≤ and < are fairly common notation for subgroups, including in group theory papers (as well as textbooks). I don't think that the comment that it's rarely used outside of elementary group theory is accurate: Aschbacher's Finite Group Theory (a central and very non-elementary text) uses it, for example. Russ Woodroofe (talk) 20:42, 28 October 2020 (UTC)
 * Adding to what has said, the notation is used in a wide variety of topics outside of elementary group theory. For example: • finite group theory paper

• group theory paper

• group theory paper

• combinatorics paper

• model theory paper

• algebraic topology paper

• automorphic representations textbook (e.g. page 8)

• topological automorphic forms book

• algebraic number theory paper

• algebraic number theory / automorphic forms paper (in Ann. Math.!) (e.g. page 1649)— MarkH21talk 07:05, 29 October 2020 (UTC)
 * OK, I have removed the disputed sentence. However, I have replaced "means" by "may mean" for suggesting that this is not a universally accepted notation.
 * By the way, a fundamental issue of the previous version of the article article was that there were no indication whether symbols and their meanings are standard, commonly used, rarely used, or specific to few authors. IMO, this may be an important question for users of this page. So, for most symbols, I have to do some bold choices. When my choice is wrong (as for < and ≤), the new structure of the article makes easy to fix my mistakes. D.Lazard (talk) 08:46, 29 October 2020 (UTC)
 * Thanks for the change, and thanks for the overhaul of the article in general! A lot of these math list articles need proper rewrites. Ideally, we can also add citations to several of the statements in the list. — MarkH21talk 08:49, 29 October 2020 (UTC)