# Requests for reopen and undelete votes for on-hold, closed, and deleted questions

Since I expect this may prove rather useful, I'm blatantly purloining Asaf's question from meta.math.se.

Beware that "short" requests such as "request reopening of <link>" may be automatically converted to comments by the SE software, so you will need to say more, such as why you think that the question should be reopened.

Please do not use this thread to engage in debates on contentious matters (e.g. reasons for closure). That should be done in a separate thread - which can be linked to from here.

If a question is reopened then please put [REOPENED] at the start of the request (answer).

Of course, each requested question may need some editing or other improvements before it is fit, and as indicated elsewhere, this is desirable, and I hope may be expedited through this thread.

(Improvements on the phrasing are welcome.)

• Not entirely necessary. There's a reopen queue now. A closed post can be put into the reopen queue by editing or voting to reopen. 3k+ users can vote to reopen (or alternatively vote against it). If this mechanism fails, then one can open a separate meta post about the question. I find that this is a more efficient process :) – Manishearth Jun 27 '13 at 21:10
• @Manishearth: Not everyone has access to the queue history, so not everyone can tell when a thread has been "outlived its review" and it is time to come to meta. In the long run, I think it's better to have one post for "run of the mill reopen votes" rather than having more and more separated questions whose answers would consist mostly of "Done." – Asaf Karagila Jun 27 '13 at 22:06
• @AsafKaragila Yeah, I see your point -- but "outlived its review" can just mean "wait a day", regardless of its queue status. So, if a reopen vote or edit doesn't push it out of the queue in a day, then come to meta (and post on this post, or separately -- IMO separate meta posts lead to better discussion, but that's just me). But if you take a look at the MSE post: Most of the recent ones are either obvious nos (closed post) user whinging about closed post, or obvious yes's (Awesome edit improved post). – Manishearth Jun 27 '13 at 22:31
• These can be dealt with fairly within the review queue itself; giving an explicit platform on meta for people to whinge or where people feel obliged to post obvious reopens is imo unnecessary. Again, I don't know much about MO or MSE, so I could be grossly wrong here :). Just giving an outsider's viewpoint. – Manishearth Jun 27 '13 at 22:32
• I agree with Manishearth: with the new "on-hold" -> edit -> add to re-open review queue mechanism, threads like this should be much less necessary. – Willie Wong Jun 28 '13 at 9:21
• @AsafKaragila Btw, this is why doing it separately is imo better, you get a lot more feedback and discussion. – Manishearth Jun 28 '13 at 16:59
• I dont want to interfere here with anything but I disagree with Manishearth about the usefulness of this Request to Reopen List. At Math SE I have observed that it works very well and efficiently to get questions reopend without making much fuzz about it. At Physics SE, we controversely discuss each question that somebody thinks should get reopend at meta seperately at length with the effect that people just discuss instead of just doing it, and almost nothing gets reopend at the end. – Dilaton Jul 3 '13 at 17:44
• Reopening questions the way people at Math SE do, has in my opinion the additional advantage that people who have less than 3000 rep and therefore not yeat access to the Reopen queue can take part in the reopen process by upvoting the answers of this post, which makes reopening of questions that deserve it more efficient. – Dilaton Jul 3 '13 at 17:54
• People are now misusing this post in order to find questions related to the closed/deleted questions to downvote and close. – Joseph Van Name Apr 17 at 3:13

[RE-OPENED and later CLOSED again]

The question How the idea of adjoint matrix has been designed? isn't great, but isn't awful, and these two answers have been posted (and upvoted) on G+ rather than as answers, which is dumb. Let's reopen the question so that the answers can be added.

As an aside, the fact that Allen Knutson basically said "this is going to be closed, so I won't contribute my awesome answer here" says something terrible about how closing is treated by MO participants. The last MO board meeting included a discussion of how to address the problem of high-rep close-happy users making the site hostile towards grad students and advanced undergrads, who we really want to be comfortable posting questions and answers, but I don't think there was any publicly visible action on it :-/.

It also bums me out that Allen and François both have the ability to edit the question to improve it, but didn't, even though they were willing to put in the effort to post answers.

• Why not move it to Mathematics? It seems like a better fit there. The user is completely new. Perhaps they'll even be better served by that site. – user9072 Oct 7 '15 at 18:01
• On the more general remarks, this would be an interesting discussion to be had. But perhaps this is not the place to enter it. – user9072 Oct 7 '15 at 18:02
• I think we should perhaps post a committed amplification on the aside here at meta, which has been much on my mind recently. (I might could get the ball rolling on that, but would need a few days at least.) – Todd Trimble Oct 7 '15 at 18:10
• I know the more general remarks belong elsewhere, but I don't have the bandwidth to properly spearhead that discussion in the foreseeable future, so I let it leak out here. I guess math.SE would be fine, but I think it's just fine for MO too. – Anton Geraschenko Oct 7 '15 at 18:14
• I gave the final vote to reopen. I don't have strong feelings on the question but I will defer to Anton whose vision gave us this site on its appropriateness. – Benjamin Steinberg Oct 7 '15 at 19:12
• It was later closed again. Perhaps it would make more sense to answer this on math.SE? – Martin Sleziak May 30 '16 at 12:57

[REOPENED]

Why was User retention rates on MathOverflow closed (on meta)? It's not a great question, I agree, but it's not exactly off-topic on meta to ask about user retention rates on the main site, and explanations for observed statistics.

• I was not involved in the closing but I witnessed it. I suspect it was the passive nature of the original question, asking other people to do all the work, when the question-asker could have done the work himself. In the end, that's what happened. I think people would have been happier if the question was asked in more of a can-do tone. But presumably the question-asker did not know it's as easy as it is to do this kind of analysis. – Ryan Budney Sep 11 '13 at 19:06

[REOPENED]

I find nothing wrong with Linear Algebra Text Book. Certainly MO.1 entertained plenty of questions about pedagogy without any controversy, and the selection of a linear algebra book with a view toward proof and standards of rigor is a perennial issue for teachers of undergraduate mathematics.

• But perhaps it should be community wiki? – Joseph O'Rourke Sep 10 '13 at 23:59
• @JosephO'Rourke Yes, good point! – Todd Trimble Sep 11 '13 at 0:06

[RE-OPENED]

I believe the post Can you write $\mathbb R^2$ as a disjoint union of two totally disconnected sets? has been closed (or put "on hold") erroneously, as a duplicate of Can you explicitly write $\mathbb{R}^2$ as a disjoint union of two totally path disconnected sets?

Certainly the question is different; note that the consensus to the first question is that the answer is 'no', and the answer to the second is 'yes'. In some sense the closed question was answered by Gerald Edgar at the other thread, but I think that answer needs to be revisited as being not quite a complete answer, since Włodzimierz Holsztyński has given what seems to be a valid objection in a comment below that answer, and no response to that objection was given.

Rather than have Włodzimierz respond at the path-disconnected thread (giving yet another answer to what is after all a different question), it seems to me proper to reopen the closed thread and have him and/or others answer. The question seems to me to be legitimately of MO level, even though it might be "trivial" for an expert like Włodzimierz.

[REOPENED]

The question A normal distribution inequality was originally phrased in a way that sounded like an exercise, and rapidly got downvoted and closed. I'm not a probabilist, bun in its current form it looks like it could be a genuine question worth re-opening.

[REOPENED]

Derek Holt, a highly respected researcher in group theory, wonders aloud why A subgroup intersects conjugacy class of every prime power order element was closed. I don't understand the closure or downvotes myself.

• Perhaps it was closed because no context or motivation was provided. But since it turns out that the answer is a consequence of a difficult and interesting result (which I didn't know myself), this doesn't seem a valid reason for closing it. – Derek Holt Nov 30 '13 at 18:19

[REOPENED]

The OP of this question Connected sum is well-defined for surfaces, proof? requests reconsideration to reopen. It was closed as a duplicate, but OP says that what is asked for was not answered at the other post; he/she wants a simple self-contained proof that doesn't invoke anything so powerful as the Annulus Theorem. OP believes that for the 2-dimensional case which is the focus here, there should be a simpler argument, and that's what is wanted. One of the comments below the question points out that with the classification of oriented surfaces in hand, well-definedness of connected sum is easy -- but insofar as the proof of the classification takes some build-up, I guess OP isn't satisfied with that either.

(I don't have a strong opinion here or a dog in the fight, but I did tell OP in response to a flag that I'd put it before the community at meta for consideration.)

[REOPENED]

An ideal candidate to get things started is this question, Preparing for set theory research. I am definitely not happy with the wording, but I understand it may be very useful for beginning graduate students, and so it probably deserves a shot.

[REOPENED]

I'd like to nominate this question. It originally got closed due to a typo, which has been fixed. It's certainly not "unclear what you are asking" any more (the original reason for closing), and it looks like a perfectly reasonable question to me.

I have a (rather quick) answer ready, and it's mildly frustrating not to be able to post it.

• The last reopen vote has been cast. – Todd Trimble Mar 24 '15 at 0:45

The question A question on $p$-approximation property from 2014 has been automatically deleted owing to lack of upvotes. While I can't immediately tell if it is a good question, it seems a perfectly reasonable one, which is unlikely to attract bad or vague answers, and might eventually get a proper answer.

For those who have high enough rep to see the question, I suggest leaving your opinion in the comments.

[UNDELETED and REOPENED]

• I cast the last vote to undelete and also voted up the question so it doesn't get autodeleted again. Let me also link meta.mathoverflow.net/questions/2232/… to again draw people's attention to this general issue. – Lucia Aug 30 '15 at 15:23

[RE-OPENED]

I think that the question How does a mathematician choose on which problem to work? was too broad in its original formulation (beginning: "How does mathematical research work?") and so I have revised it in a way that I hope allows it, as a soft-question, to be (re)re-opened. It is certainly not intended as a finalized product; only a more focused question than the original version.

I also re-paste here the edit summary that I left (specifically for its final sentence):

I have substantially edited this question in response to its being re-closed: I removed some of the more general questions from the body, and tried to focus on the title question. If anyone feels that the change is too great, or otherwise inappropriate, I only ask that you revert the edit.

(If the edit is reverted, then [at least] I will not expend more energy on re-formulating the post.)

[REOPENED]

Parameterizing rotations of a cube

was asked and answered, but I don't see a reason for closing it.

• I think you're right, Gil, but I'll wait for another vote to reopen before applying moderator power. – Todd Trimble Dec 2 '15 at 18:05
• I cast a vote to reopen mainly as I do not see the point of such "after the fact closure." We are not going to delete the post, are we? // @ToddTrimble there is only one vote missing now. – user9072 Dec 2 '15 at 18:16

[UNDELETED]

This is an undelete request for an answer on meta: namely, quid's answer to my question Some proposals for modifications of the process of closing/reopening questions . The answer was accepted, but yet got deleted when quid left the site. This was not quid's intent, and I also checked that quid was fine with the answer being undeleted (see http://chat.stackexchange.com/rooms/37812/discussion-on-answer-by-sergei-akbarov-mathoverflow-user-jailed).

• This is a reasonable request, and I think there should be one of these on meta to indicate the possibility of this type of undeletion. I think it is better for the site if future requests of this nature are made directly to the moderators@mathoverflow.net, and not on a public forum. (I am willing to expand on this through email if asked.) Gerhard "Seems More Respectful To Me" Paseman, 2016.04.16. – Gerhard Paseman Apr 16 '16 at 19:33
• It seems pretty straightforward to me, and I don't see what is sensitive about the request that cannot be discussed publicly. – Lucia Apr 16 '16 at 19:40

[REOPENED]

I'd like to suggest reopening Covering systems. As I wrote in a comment,

Why is this closed? Covering systems are a recognized area of research in Number Theory. It's known that in an irredundant cover with a modulus divisible by a prime $p$ there are at least $p$ moduli divisible by $p$. This asks whether, if there is a modulus divisible by a power of a prime $p$, there are at least $p$ moduli divisible by that power of $p$. Seems like a reasonable research question to me.

[Also, I think I can answer it.]

• I've just cast a 5th vote to reopen. Let's see if anyone who voted to close leaves further comments – Yemon Choi Oct 29 '16 at 21:55

[REOPENED]

A question Finite groups with no elements of order $p^2q$ originally closed was heavily edited by Yves Cornulier and Nick Gill.

There are three votes to reopen already, but the question is already a bit out of sight, thus this posting.

[REOPENED]

I think people were pretty hasty in shutting down this question: Shape of axioms in abstract algebra. I could just barely squeeze in some highly relevant content and context in a comment before the thing was shut down. I request that this be reopened.

• I had voted to migrate to math.SE, since I think the question is a fine, but a better match for them, but it seems that migration was not the actual result. Is it still possible to migrate a question that has been placed on hold? If not, I guess I'll vote to reopen, especially if Todd has something to say. – Joel David Hamkins Jul 24 '13 at 21:05
• @JoelDavidHamkins: moderators could still migrate it. If you would like this, just flag the question with a moderator attention flag giving this request as the reason for flagging. (This is to answer the technical question, I have no opinion on this question.) – user9072 Jul 24 '13 at 21:25
• I have suggested an edit which may place the question more properly in the realm of mathoverflow.stackexchange. It is still on the naive side, although one can find answers on the lines of finding mostly equational bases for theories which include or may be included by the definition theory. – The Masked Avenger Jul 24 '13 at 22:33

[REOPENED]

The question

Finding all local maximum points of a function?

does not seem as trivial to me as has been supposed. Sure, one can set the gradient equal to zero, but how does one actually prove that the only solutions are the "obvious ones"? At the very least it seems worth leaving the question open for a while.

I think some votes to close here were due confusion related to an earlier version of the question where the OP experienced technical difficulties. The objection that the OP's SBTMs are finite state machines is incorrect. Moreover, SBTMs are not completely ad hoc or unmotivated, the computer you are using to read this sentence is essentially an SBTM.

• The objection that the OP's SBTMs are finite state machines is incorrect. Why? Perhaps we are interpreting the definitions differently? – fedja Apr 28 at 14:39

[REOPENED]

I think this question:Are there infinitely many natural numbers not covered by one of these 7 polynomials? should be reopened. Please see the comments by me and Joel in main.

• I think the question in its current form is actually quite bad, but the additions from the comments by the OP help. Specifically, it asks how he can prove something that he only suspects to be true, rather than asking whether it is true. And with no further details, the question is way too specific (I mean, if I was to ask the same question about the same polynomials except I change one coefficient in one of them, why would that not also be an equally good question?) – Tobias Kildetoft Apr 30 '14 at 19:24
• @TobiasKildetoft: I think if you change the coefficients it would still be an interesting question, as I mention in my comment. The general question, of which the original one is a special case, is unclear to me. The current question is clearly stated, and the answer is not at all obvious. You may not be interested in the question, which is fine, but note that the question was closed as being not up to research level (without indicating any answer). – Lucia Apr 30 '14 at 19:32
• I agree that the general type of question is of interest. But focusing on a special case is not unless that special case has some additional property, either coming from something else or for some reason being "generic". An answer to this question that would not work for any other set of polynomials at all would for example be completely uninteresting, but answer the question. – Tobias Kildetoft Apr 30 '14 at 19:38
• @TobiasKildetoft: I think you are wrong here, but of course you are entitled to your opinion. – Lucia Apr 30 '14 at 19:39

The question How to find generators to Mordell weil groups of elliptic curves? was originally phrased in the narrow context of inquiring just about the software Sage. I had voted to close that, but the revised more general question seems worth reopening. I have cast my vote to reopen, but am not sure that the revised question has received enough attention.

(Also, this meta question now has too many answers, and perhaps it's better to start a new thread with the same intent. When I wrote this reopen request, the system wanted to know if with 30 answers to this question whether I really wanted to add another one.)

[REOPENED]

• I would say that a message popping up when you post an answer is a small price to pay for having everything gathered one place. – Tobias Kildetoft Sep 2 '14 at 17:59

[REOPENED]

"Find a TSP tour passing through at least one node in each set of nodes" was initially unclear, but the author has now clarified it into a real question (and I corrected the English): Is there a PTAS (polynomial-time approximation scheme) for this problem?

[REOPENED]

The question Lexicographic order on increasing $k$-tuples by a first-time poster was closed as "unclear what you're asking". I have rewritten it so that (I think) it is now clear. It is not a hard question, but I think it probably has a nice answer.

[REOPENED]

This question was heavily downvoted and closed: When a compact topological manifold with boundary is a ball? Color me ignorant, perhaps, but I wondered if it were as trivial as the downvotes and closure might suggest.

Although it is a question for the topological category, a very similar question but for the smooth category was upvoted and answered last year, and the answers suggested there was interesting mathematics: The boundary of a domain whose interior is diffeomorphic to the ball.

• The downvotes and closure do not necessarily suggest it is trivial. Rather they might just suggest the question is terribly written and thus deemed unsuitable, irrespective of its precise mathematical content. Let me add that I do not have a personal opinion on the content of this particular question (I also did not vote on it), but I am of the opinion that there are minimal standards on the presentation that should be enforced. It might be a good idea though to explain this when closing. – user9072 Nov 11 '15 at 19:54
• @quid We've both been here a long time. I said they might suggest that. No explanation is given, so we are left guessing what the problem actually is. I don't think the question is terribly written; do you think that? If we tweaked it to read, "Let $X$ be a compact topological manifold with boundary, and suppose its interior is homeomorphic to an (open) ball. Is $X$ a (closed) ball?", then is it still terribly written? I wouldn't really think so. – Todd Trimble Nov 11 '15 at 20:00
• Point taken on the "might." The rewrite you propose is still a very poorly presented question, as it lacks all context and motivation. By contrast the well-received question you reference gives some context. – user9072 Nov 11 '15 at 20:07
• @quid There is ample precedent for short, snappy questions which don't include motivations/context, that have been well received. It is highly questionable whether questions that are short and snappy are ipso facto "poor". In any case, if this is the only objection, then I have to think that the reaction was likewise "poorly presented" (except perhaps for the possibility it does have a trivial answer I have overlooked). – Todd Trimble Nov 11 '15 at 21:18
• Yes, unfortunately, that's true. Many a complicated debate could have been avoided would there be only consensus that the official guide, which asks for context, on how to ask a question is somewhat binding (and to be sure that guide was written by "us" not SE). Of course, a snappy question can "fly" and if it flies it might even fly higher than the same question with context. But, first, it is more fragile so to say. And also it does not alter the fact that it would still be a ultimately better question with some context even if it might get less upvotes. – user9072 Nov 11 '15 at 22:22
• @quid I added already a comment to the post suggesting adding some context. I can see the point of your last comment, but I think it would be hard getting community consensus on making it a rule. – Todd Trimble Nov 11 '15 at 22:43
• I saw that comment. Thanks for adding it. To reply also to your second remark from the earlier comment: there is no disagreement there. I said right away 'It might be a good idea though to explain this when closing.' Certainly I am not blind to the fact that a closure without comment and the most generic reason is not optimal. – user9072 Nov 11 '15 at 22:48
• I don't agree at all the the presentation was particularly poor, and find it appalling that it got 5 downvotes and was closed within an hour. It could have been written better, sure, but I strongly agree with Todd's remark that the question is self-motivating. – Eric Wofsey Nov 12 '15 at 16:29
• @EricWofsey is the question better with or without the context? – user9072 Nov 12 '15 at 16:35
• @EricWofsey Agree with you very strongly. Again I would ask closers: if you are closing because you think the question is "not research level", then please please please take a moment to ask yourself whether you know enough about the subject to make that call. (If you don't, then leave it alone.) If the real reason for closure is that you think it's not well written, then please leave a note for the poor newcomer explaining how the post might be improved. – Todd Trimble Nov 12 '15 at 16:35
• @quid: Obviously it is better with context, but that doesn't mean it was a bad question that needed to be put on hold, let alone put on hold with the swiftness and accompanying downvotes normally given only to calculus questions and their ilk. – Eric Wofsey Nov 12 '15 at 16:40
• I was one of the people voting to close. I thought there were trivial counter-examples. I realize now that my trivial counter-examples are not counter-examples. My apologies to the OP. – Hugh Thomas Nov 12 '15 at 16:43
• @EricWofsey if what are in my opinion proper procedures would be followed this and related situations would go over much more smoothly. The users showing your type of reaction in such situations are in my firm opinion in the end not all that helpful either, but rather make a bad situation worse. – user9072 Nov 12 '15 at 16:47

[REOPENED]

The question Identify one group of linear transformations was closed as "unclear what you're asking". Afterwards it has been edited and clarified. I don't see what is still "unclear" in this question.

[UNDELETED] [REOPENED] [CLOSED]

I would suggest to undelete/reopen https://mathoverflow.net/q/328312, as a courtesy and sign of respect, and then hopefully one of our experts can answer it.

I know, I was one of those who cast a vote to delete, when I was still under the impression that this was posted under a false name. Somehow the software allows to retract close votes but not delete votes.

Edit GRP 2019.07.11 The question was deleted by community user on May 23. I think it should be undeleted as it makes an excellent example of how to not ask a question on MathOverflow. It can also be used to help design a format for others to follow in asking questions suitable for this forum. I also reference it in one of my posts on meta. End Edit

• I find some of the comments on that question extremely, extremely dispiriting. What happened to the MathOverflow I knew where people acted with some charity towards fellow researchers who maybe, just maybe, did not have the same undergraduate education or simply do not have the time to reinvent the wheel? – Yemon Choi Apr 17 at 20:34
• I should explain that I am more likely to downvote or vote-to-close a question which seems to be on topic X by a student in X who should be finding the answer to a question on X as part of their studies of X. Whereas a specialist in Y asking a question on X that people who study X can answer easily was surely one of the original princples/purposes of MO – Yemon Choi Apr 17 at 20:37
• @Yemon, Sympathetic as I am with your position, we still lack a standard of how researchers in Y can ask questions about X. I am still surprised at the way this question was posted, and find it hard to distinguish from a question asked by student X who has not tried even a Google search. Perhaps you can think of a better way to handle this? Gerhard "What If Asker Is Unreal?" Paseman, 2019.04.17. – Gerhard Paseman Apr 17 at 22:05
• My opinion (visibly not shared by some of you) is that I think the rules should aim at being the same for all people and acted regardless of the possible (now verified) identity. – YCor Apr 18 at 9:18

[REOPENED]

Please have a look at the comments at https://mathoverflow.net/questions/135605/how-to-discover-counterexamples-and-required-objects? and consider voting to reopen.

• On a procedural note: why is this (already) posted here, when the question had already its own meta question? (In addition to being still on the frontpage, even now hours later, so it was presumably fairly to the top when this was posted.) – user9072 Jul 3 '13 at 12:55
• @quid, I didn't see that meta question. There was no link to it at the original, and nothing in the name of the meta question to draw my attention to its relevance here. Shall I withdraw this question? – Gerry Myerson Jul 3 '13 at 13:38
• thank you for the reply. I do not think it is necessary to withdraw this post now. My comment was also meant to help form some consensus when one should post here. I take you reply as you agreeing with me that in principle one should rather not do so in parallel with an existing meta-disussion on the question. I agree the meta-question in this case was hard to notice, which I tried to fix now, before even noticing you reply. – user9072 Jul 3 '13 at 13:43

[REOPENED]

The question

The probability for a streak when tossing a coin

was closed quickly, but as far as I know, this is not an exercise. There is a complicated approximation in Feller's classic text.

As suggested in this question, I put more discussion in a separate thread.

[REOPENED]

Question on a concrete example of n points has been improved considerably since it was closed and might be considered for re-opening.

[Undeleted; Reopened]

If normal with respect to prime base then normal for all bases was closed as not being research math. I nominated it for reopening, after leaving a comment establishing its research content. There were four votes to reopen; then, OP chose to delete the question.

So now I am asking for the question to be undeleted and, should that happen, for it to be reopened.

[UNDELETED]

I propose that this question should be undeleted: Reduced ring with all non-prime ideals finitely generated

It was deleted by the OP despite having a substantial answer by Keith Kearnes. Keith has re-asked the question and re-posted his answer at Reduced ring with all non-prime ideals finitely generated