Wikipedia talk:WikiProject Mathematics/Archive/2018/Apr

Mathcurve
Hello, I visit en.wp very seldom, so I leave you discuss this between yourselves : are external links to (specifically related subpages of) mathcurve appropriate in pages about curves, or not ? (I tried to convince one of you they are, but he disagrees). Anne Bauval (talk) 18:43, 2 April 2018 (UTC)
 * When Robert Ferreol first started putting these external links into articles I reverted them per WP:ELNO and WP:COI, but he wore me out and I eventually stopped doing this. This does not mean that the problems with these additions had gone away. The main problem in my mind has to do with Mr. Ferreol. For these links to be acceptable, he would have to be a recognized authority on curves. The award for his website in 2008 does not confer this type of recognition. I fully support 's continued removal of these links. --Bill Cherowitzo (talk) 19:58, 2 April 2018 (UTC)
 * Personally, I don't have a problem including these as external links. They seem to be a useful reference, supported by lots of images and animations.  I don't see any explicit ELNO violations.  WP:EL has an advisory that links that do not meet WP:RS may be considered for inclusion, but there is certainly no ban on them, and we regularly include links to sources that do not meet RS.   Sławomir Biały  (talk) 11:56, 3 April 2018 (UTC)
 * Well if Robert Ferreol is adding the site systematically to curve articles, then arguing WP:COI probably has some merit. However imho the site as such can be appropriate as an external link for various curves and passes WP:EL. So if other editors want to add it to articles they write or maintain, then I see nothing wrong with that.--Kmhkmh (talk) 17:06, 3 April 2018 (UTC)

Draft:Gabriele Vezzosi
Does not obvioisly meet PROF unless his work is notable. Reads a little spam like to me. Comments to the Draft talk page please Legacypac (talk) 23:57, 7 April 2018 (UTC)


 * His works (e.g., those on derived algebraic geometry are notable; even a non-specialist like me can recognize his name. I can’t see why it is a spam. (I will copy this comment to the talkpage) —- Taku (talk) 20:09, 8 April 2018 (UTC)

Template:Unsolved at TfD
Discussion here. --JBL (talk) 02:27, 9 April 2018 (UTC)


 * (And kept. --JBL (talk) 01:58, 11 April 2018 (UTC))

Please fix incorrect nesting of sub/sup tags on pages as identified by Linter
We plan to complete replacing Tidy with a different tool on all wikis by end-June. As part of this, we have identified pages that need some markup fixed. This is exposed by the Linter extension via the Special:LintErrors page. Only linter issues in the high-priority categories need to be addressed. It is sufficient to prioritize articles for now.

One of the linter categories is the mw:Help:Extension:Linter/html5-misnesting category. You can see the list of linter issues in the Article namespace here. Of those, there are a subset of issues that primarily affect math and other pages that use math. The effects can be particularly important here as this example demonstrates. The rendering on the left is what you see on the wiki right now. The rendering on the right is what it will change to when Tidy is replaced. Notice how r kn = kn + 1 has changed to r kn = kn + 1. This is because the quotes are improperly nested in the  tag and needs to be fixed to reflect the intended rendering.

The edit links in this listing of article namespace html5-misnesting errors shows you the exact malformed wikitext. My recommendation is to fix pages where the  and   tags are shown as being misnested. I am also happy to give you a separate list of pages where sub and sup tags are misnested (about ~300 in all). Let me know if you have any questions.

SSastry (WMF) (talk) 21:22, 19 March 2018 (UTC)


 * having just glanced quickly at the first few pages of the list you attached, the cases of sub and sup seem very sparse, so I think a separate list of just those would be very helpful. --JBL (talk) 22:19, 19 March 2018 (UTC)
 * , list of pages with misnested sub tags, list of pages with misnested sup tags SSastry (WMF) (talk) 03:43, 20 March 2018 (UTC)
 * Thanks,, that's helpful. It looks like this later list is not dynamic (?) -- that is, I just fixed a few and they're still listed there.  Is that right?  --JBL (talk) 12:37, 20 March 2018 (UTC)
 * , yes, it is not a dynamic list, but I will resubmit the query and refresh it periodically. SSastry (WMF) (talk) 14:19, 20 March 2018 (UTC)
 * great, thanks. (I have done a dozen or two so far, will keep plugging away in my spare time.)  --JBL (talk) 15:28, 20 March 2018 (UTC)
 * Problems seem to be with mixing italics and / . x i creates an error, better placement requires xi . Fixed on Utility maximization problem.--Salix alba (talk): 22:58, 19 March 2018 (UTC)
 * That's the predominant reason. The other alternative would be . Though, in this case, it might be better to use var. --Izno (talk) 00:19, 20 March 2018 (UTC)
 * No, I don't think that's throwing errors; it's just when the parenthesization on italics doesn't nest with the parenthesization on sup and sub tags. --JBL (talk) 12:36, 20 March 2018 (UTC)
 * The other alternative to fix the issue. --Izno (talk) 14:10, 20 March 2018 (UTC)
 * Sorry, I think we've had a miscommunication: when you wrote "the other alternative", did you mean the other *working* alternative or the other *problematic* alternative? (I first read it as the latter, hence my reply, but if you meant the former then I agree entirely.)  --JBL (talk) 15:05, 20 March 2018 (UTC)
 * The former, hence the attempted clarification. --Izno (talk) 15:48, 20 March 2018 (UTC)
 * I found a few more, Rook polynomial, Rotation group SO(3), and Group (mathematics). But I probably missed some as my eyes quickly scanned over a ton of non-math articles.  By the way, could someone look near the change I made at the group article, and see what's up with that   tag?  I've never seen that before and I don't know what it's supposed to be doing.   –Deacon Vorbis (carbon &bull; videos) 00:57, 20 March 2018 (UTC)
 * It appears that  is supposed to surround the titles of cited references. Its use there does not fit that description, and it does not appear to make a visible difference in the article. I think it can safely be removed. —David Eppstein (talk) 01:27, 20 March 2018 (UTC)
 * The W3C allows cite around any cited material; the WHATWG allows it only around titles. Anyway, it is being used wrongly here. --Izno (talk) 01:58, 20 March 2018 (UTC)
 * Well, I just noticed the example you gave hadn't actually been fixed, so I did so, and now the example doesn't really work to point out what's going on. I'm not sure if you want to leave it in place to use as an example, so just revert the change if so, I guess.  –Deacon Vorbis (carbon &bull; videos) 01:21, 20 March 2018 (UTC)
 * , I edited the url and added the oldid to it so it continues to be a useful example. SSastry (WMF) (talk) 03:46, 20 March 2018 (UTC)

Some of these seem not directly fixable; for example, in Elias M. Stein, the problem is the following: Presumably, what's going on is that the template slaps  ...  around the title of the thesis. (And indeed the effect in the infobox there is funny: the p is not italicized.) But it is not clear to me what the "right" way to deal with this is. (There are also examples like Georgia Benkart, where the problem is the title field in the cite book template.) --JBL (talk) 20:25, 20 March 2018 (UTC)
 * Presumably it would work (at least in terms of getting unsurprising italicization, if not necessarily optimal appearance) to replace the html math formatting with &lt;math&gt;. Similar issues occur within the unsolved template, which also italicizes its argument (e.g.). —David Eppstein (talk) 20:43, 20 March 2018 (UTC)
 * In this case  seems to work. The first  end the italics, before the and the second  starts it again after the meaning the start and end of italics are not either side of a tag. You can check the new render behaviour by adding   to the url. E.g. https://en.wikipedia.org/w/index.php?title=Elias_M._Stein&action=parsermigration-edit --Salix alba (talk): 00:08, 21 March 2018 (UTC)

Just a gentle ping. I noticed that the sub-tag affected pages has not moved in over a week and is at 57 entries. Same with sup-tag affected pages that is at 161 entries. Another burst of fixing might bring the former to zero. SSastry (WMF) (talk) 17:29, 30 March 2018 (UTC)
 * real life intervened :-/. I have made a bit more progress on sub tags, but I don't forsee a lot more in the next few days.  --JBL (talk) 01:44, 3 April 2018 (UTC)
 * No worries. You all have till end of June to get to them. I was mostly making sure this was on your radar with a little nudge. SSastry (WMF) (talk) 03:55, 3 April 2018 (UTC)
 * I think that I have fixed every instance that does not involve incomprehensible template interactions. But there are a lot in the latter category for the sup tags.  At least one of them was brand new!  --JBL (talk) 20:28, 5 April 2018 (UTC)
 * Thanks, looks good. The sup category has 86 entries (but not 86 pages). There are probably only a handful of math pages in there if you want to only focus on math pages. But, whatever you can do is helpful. Ya, till we actually replace Tidy, new entries might show up as editors introduce newer erroneous markup on pages. After that, preview will give them immediate feedback where it is broken. SSastry (WMF) (talk) 01:20, 7 April 2018 (UTC)
 * A bunch of the ones in the sup list do not appear to have any sup tags in them at all, hence my remark about "incomprehensible template interactions." For example, this appears to be true of Scientology_and_the_Internet, HMS_Ark_Royal_(R07), Hero's_journey, Chris_Harris_(Texas_politician), Kim_Brimer, NBA_Live_99, Samuel_Ealy_Johnson_Jr., and New_York's_9th_congressional_district.  (This is not meant to be comprehensive, they're just all among the top entries on the current version of the list.)  --JBL (talk) 02:12, 10 April 2018 (UTC)
 * The one in Hero's_journey is because of and its interaction with https://phabricator.wikimedia.org/T14974. That entity is the ";" char and it introduces a newline and breaks a sup tag generated by the the ref template. Anyway, it is okay if you cannot fix them all. Not sure why that template is using ; and other chars for ref ids. SSastry (WMF) (talk) 03:39, 10 April 2018 (UTC)
 * I think I've now reached the point that I've fixed everything that is broken for reasons I can understand. (For example, not Hero's journey.)  --JBL (talk) 16:41, 11 April 2018 (UTC)
 * Thanks very much! This is good for now. Just after Tidy is replaced on enwiki, I'll update those lists so any new entries introduced in the interim can be fixed. But, once Tidy is replaced, these errors won't make it through since editors using preview / verifying their edits will see the brokenness right away. SSastry (WMF) (talk) 21:30, 11 April 2018 (UTC)

Ending the system of portals
Hello, there's a proposal to delete all Wikipedia portals. Please see the discussion here. --NaBUru38 (talk) 14:00, 14 April 2018 (UTC)

Algebraic Geometry (journal)
Algebraic Geometry (journal) has been proposed for deletion by, one of the regular editors on articles about academic journals. It looks to me like a legitimate new journal, but possibly one that is too new to pass WP:NJournals. Anyway, if you disagree with this proposal (and especially if you can find third-party publications about this journal that might increase its apparent notability) please feel free to unprod. —David Eppstein (talk) 18:46, 14 April 2018 (UTC)
 * I was unable to find sufficient sourcing for notability, but there is sourcing in catalogs for basic facts about the journal. I suggest we redirect to European_Mathematical_Society, where it is mentioned. It could be turned back into an article if it gains an impact factor or other signs of notability. --Mark viking (talk) 20:55, 14 April 2018 (UTC)
 * (edit conflict) I was not impressed with the deletion rationale. The in-practice standards for academic journals seem to be basically 0, and this one is fully indexed in both the selective MathSciNet and Zentralblatt databases (which contradicts the deletion rationale). For personal reasons I am not going to remove the prod, but I would like to encourage others to do so. (I mean, there's a case to be made for nuking a large portion of the academic journals in Wikipedia, but as they go this one is less deserving of nuking than any of dozens or hundreds of others.) --JBL (talk) 20:58, 14 April 2018 (UTC)
 * Mark viking's suggestion is reasonable, too. (Although you should look at what allegedly passes for sourcing and notability in this corner of WP: e.g. Current_Opinion_(Current_Drugs).) --JBL (talk) 21:08, 14 April 2018 (UTC)
 * I de-prod'ed the page since it looks like the question of what to do with it needs a little more discussion, and for a topic like this we don't really need to hurry. Redirecting to European_Mathematical_Society and carrying over the AMS and Zentralblatt citations to provide sources for basic facts sounds like a reasonable idea to me. XOR&#39;easter (talk) 16:42, 15 April 2018 (UTC)
 * Why is EMS the right redirect target, if it is to be redirected? It looks to me that they are merely the printers, not the actual owners of the journal, which are the same people who run Compositio Mathematica. Maybe that would be a better target? —David Eppstein (talk) 18:56, 15 April 2018 (UTC)
 * You raise a good point and I think redirecting to the owners would be fine, except that we have no article for Foundation Compositio Mathematica at present. EMS seemed a reasonable runner up target. --Mark viking (talk) 20:13, 15 April 2018 (UTC)
 * Hmmm, yes. Perhaps we should move Compositio Mathematica to Foundation Compositio Mathematica, make the current text a section, and then merge and redirect Algebraic Geometry there as well? XOR&#39;easter (talk) 21:07, 15 April 2018 (UTC)

Requested move of Symmetric graph to Arc-transitive graph
A move request is ongoing at Talk:Symmetric graph, but it has little participation. Input would be appreciated. Dekimasu よ! 12:42, 18 April 2018 (UTC)

Proposed deletion of Pseudomathematics


The article Pseudomathematics has been proposed for deletion&#32;because of the following concern: "This uncited article is, so far as it goes, largely a piece of original research. The term 'pseudomathematics' rarely crops up, and when it does it's used as a short hand way of saying that conventional mathematical techniques have been misused or misapplied. An example would be the backtest overfitting of financial data modelling, where the prefix 'pseudo' has the same general meaning as it does in 'pseudo-democracy'. In other words, there is no field of endeavour called 'pseudomathematics'."

While all constructive contributions to Wikipedia are appreciated, pages may be deleted for any of several reasons.

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

Please consider improving the page to address the issues raised. Removing will stop the proposed deletion process, but other deletion processes exist. In particular, the speedy deletion process can result in deletion without discussion, and articles for deletion allows discussion to reach consensus for deletion. Eric  Corbett  01:24, 11 April 2018 (UTC)


 * Now at AfD instead. --JBL (talk) 01:57, 11 April 2018 (UTC)


 * Pseudomathematics has been kept, with the closing comment, "Consensus is that this is a notable topic. Consensus also indicates there are considerable OR issues to address." I'm not so sure about the latter half; my read of the overall opinion was that the article quality was poor, but OR wasn't among the reasons why. XOR&#39;easter (talk) 14:48, 19 April 2018 (UTC)


 * Are you intending to do anything about improving the article quality to at least an acceptable standard? Eric   Corbett  17:02, 19 April 2018 (UTC)

Proportion
Hi all. There is a dispute at Talk:Proportion that can use attention from the members of the project. —- Taku (talk) 21:54, 26 April 2018 (UTC)

RfD
FYI, I've added a listing at Redirects for discussion/Log/2018 April 26. Further comments are welcome. –Deacon Vorbis (carbon &bull; videos) 03:09, 27 April 2018 (UTC)

Excluded middle
About "Schröder–Bernstein theorem",, , , I wonder, how do we feel about excluded middle? Should its use be noticed always, or sometimes, or never, or what? Boris Tsirelson (talk) 11:20, 28 April 2018 (UTC)


 * Since intuitionists are a very small minority of mathematicians, I would not mention the use of excluded middle unless the article in which it occurs is primarily of interest to intuitionists, i.e. very rarely. Or if the article is about something in logic which is equivalent to the law of excluded middle, such as Peirce's law. JRSpriggs (talk) 01:06, 29 April 2018 (UTC)
 * I agree that intuitionism is of few interest for most mathematicians. But this is not the case for intuitionistic logics, which are the logics used by the most powerful proof assistants, such as Coq. This means that a proof using Schröder–Bernstein theorem cannot be easily formalized (that is checked by a computer), with the present state of the art. This may interest many mathematicians, and therefore deserves to be noticed in the article. Thus, the sentence disputed in the above diffs must be kept, but requires clarification. D.Lazard (talk) 08:46, 29 April 2018 (UTC)
 * I guess my feeling is that it depends on the result. It would strike me as pretty silly to point out that some deep result in set theory or functional analysis depends on excluded middle, since you really can't develop the underlying theory without excluded middle.  But Schröder–Berstein is such a basic result about the structure of cardinalities that it may be worth pointing out.
 * As for the dispute over the meaning of the word "constructive", I'm not going to go there. If that's the problem, then just reword to avoid that term. --Trovatore (talk) 08:59, 29 April 2018 (UTC)
 * I agree with Trovatore.  Sławomir Biały  (talk) 12:20, 29 April 2018 (UTC)
 * Me, too. --JBL (talk) 13:53, 29 April 2018 (UTC)
 * About proof assistants: really? As far as I know, the Jordan curve theorem is formalized successfully. Without excluded middle?! Boris Tsirelson (talk) 10:53, 29 April 2018 (UTC)

Lévy–Steinitz theorem
I have created a short new article titled Lévy–Steinitz theorem. The theorem states this: I found that in the List of permutation topics there was no section on rearrangements of series, and I created one, titled Mathematical analysis, which now lists, among other things, this theorem.
 * The set of all sums of rearrangments of a given series of vectors in a finite-dimensional real Euclidean space is either the empty set or a translate of a subspace (i.e., a set of the form v + M, where v is a given vector and M is a linear subspace).

I have added links to the new article from the following articles:
 * Paul Lévy (mathematician)
 * Conditional convergence
 * Riemann series theorem
 * List of permutation topics
 * Ernst Steinitz
 * Rearrangement
 * Steinitz's theorem (In this article the link is in a hatnote.)

I have also created the following redirect pages:
 * Levy–Steinitz theorem
 * Levy-Steinitz theorem
 * Lévy-Steinitz theorem
 * Lévy Steinitz theorem
 * Levy Steinitz theorem

(I haven't yet created redirects with a capital "T"; probably I'll do that soon if no one else does it first.)

So now:
 * The article could be expanded.
 * More links from other articles could be created.
 * Possibly other improvements can be done.

Michael Hardy (talk) 18:10, 29 April 2018 (UTC)