# Requests for Reopen & Undeletion Votes (volume 01/2021 - today)

The purpose of this thread is to focus the attention of the community on posts that may require reopen and undeletion votes. A request should be posted as an answer below (one request per answer).

Some guidelines:

• Please be polite, and respect the many different viewpoints in our diverse community. This goes for the person making the request as well as those commenting on it.

• There is a reopen queue. Please wait until a post has gone through this queue, before posting here. Notice that the first edit after the question is closed pushes the question into the reopen review queue if the edit is done within 5 days of closure, and so does a reopen vote. (If the review has already been finished, it is shown on the timeline of the question.) When in doubt, wait 24 hours after the last substantive action.

• To inform readers of the current (and past) states of the targeted post, please add the information Reopened or Undeleted at the start once the request has resulted in some action. (If the action is undone, add this too, like Reopened, Reclosed.)

• Do not only post a request, like "request reopening of link". Instead, make a case for your concern. Yet keep in mind that it can be easier to get your request handled if you try to frame it in a way that takes the feedback the post received into account positively rather then seeking confrontation. Also, try to improve the post before posting here.

• In case of "small" requests, like one missing vote, it can make sense to ask in chat instead of posting here. The room CURED is a reasonable place for such requests. The same guidelines apply there.

• If you are involved in the thread which you post about (e.g., you asked the question or you answered it), please disclose this.

Earlier versions of the thread that served as a model:

• If I understand correctly, it is not ok to post undeletion requests if one of the deletion votes was from a mod right? I assume that it is not, but I just want to be sure. Also, feel free to delete this comment if it is appropriate, or ask me to delete it and I will. – HereToRelax Apr 7 at 3:45
• @HereToRelax To weigh in on that, I don't see why it wouldn't be OK, but only a moderator could help you. One would guess that it would be more appropriate to flag, but that doesn't really allow for back and forth discussion. – Matt Samuel Apr 7 at 20:25
• You are always welcome to discuss questions which a moderator has voted to delete. If you are asking about this question, it is worth noting that my delete vote was cast in 2019, before I was a moderator. I stand by that vote---even with the minor clarification in the comments, the question still lacks context---but you are welcome to discuss the question. If you can find two people who agree with you, the question can be undeleted. – Xander Henderson Apr 8 at 14:47

Undeleted

Please undelete Functional Analysis: Finding finite functions over different norms as the question asker self-deleted his/her own question one day after receiving an answer.

Reopened

Please consider reopening this Question, which was closed for lack of context.

Yet the original opening paragraph gives the following context:

I have a young group of kids (30) playing soccer and they need to be put into 6 teams of 5 players for each round of matches. All 6 teams play at the same time on adjoining fields.

I make a point of bringing this to the Community's attention because there has been something of a historical pattern with these kinds of problems. The asker has (or claims to have) a real world motivation for asking about a certain kind of block design. The Question has a definite mathematical formulation and solution, often one that is not obvious without a certain amount of trial and error computation (though occasionally the literature provides an answer).

None of the five close voters left a Comment to record what in the way of additional context would improve the Question to their satisfaction.

• Most combinatorial design questions require decades of research and computational time to answer, so it infuriates me when questions like these are closed with a comment like "well, what have you tried?". Presented with such a hard problem in real life, most mathematicians would be stumped, let alone laymen. – Mike Earnest 2 days ago
• @MikeEarnest: Right, a typical user might well not know how to tackle problems that they have a real world motivation for. I want to see their context, but "what have you tried" is not the gold standard here (though this user did suggest they'd thought about complete block designs because they said it wasn't what they wanted). – hardmath 2 days ago

### Undeleted

https://math.stackexchange.com/a/3980921/43608

This is a deleted new answer to an old question (from february 2019), by a user that has been on MSE for 1 year and 10 months, but does not seem to have questions or answers yet.

The deleted answer is short, arguably too short, but would be at least a good hint in the correct direction (it was for me, when I tried to figure out whether to vote to delete or not in review queue).

The question is ambiguous, as noticed by the two answers already here, but I think the new one has the correct interpretation (that the coefficients $$a,b,c$$ are independent of $$n$$), since it leads easily to a unique solution, as expected.

I believe the deleted answer is correct while the two undeleted ones are not, and thus deserves to be undeleted.

• Looks to be undeleted now. – Teresa Lisbon Jan 12 at 5:53

I want to know why the reason for closure of this question has been given as:

Questions about choosing a course, academic program, career path, etc. are off-topic. Such questions should be directed to those employed by the institution in question, or other qualified individuals who know your specific circumstances.

I do not see any reason for closure of this question.

• The close reason is, I think, nonsense. However, the question does (in my opinion---note that I say this not as a moderator, but as a disinterested third party) deserve to be closed. It lacks context. – Xander Henderson Mar 2 at 23:44
• @XanderHenderson: Well, in that case am I permitted to delete the question because it is not useful for anyone anymore? And secondly, can you explain what more context could I have added in there? I didn't understand the statement of the question itself, so what ideas should I have been added there? Note that I know how to ask good questions on this site, as you can see my profile. – Light Yagami Mar 2 at 23:47
• See How to ask a good question. In your case, I would suggest that the problem seems to depend on the definitions of "cofactor" and "minor". Quoting those definitions in your question would likely help to provide context (of course, a careful reading of those definitions might also clear up the confusion). – Xander Henderson Mar 2 at 23:55
• I should also point out, again, that when I say that the question should be closed for lack of context, I am merely expressing my opinion. I am not expressing the opinion of the moderating team, nor making a statement about site policy. I left the question in the state it was in an hour ago, but with a close reason that makes more sense. Other users may disagree, and may feel that the question ought to be reopened. That said, providing additional context will make it easier for others to vote to reopen. – Xander Henderson Mar 2 at 23:57
• The question has been deleted. – Gerry Myerson Mar 24 at 22:34

Undeleted and reopened

Please consider undeleting and reopening Is an ideal finitely generated if its radical is finitely generated?. This is a very natural question to which there are no immediately obvious counterexamples, and it has received a couple nice examples in answers.

It seems to me that this is exactly the sort of question that this site was built for: questions that may naturally occur to many people (not just some exercise that is of no particular interest), do not have obvious or "standard" answers that can be found in every textbook on the subject, and by having an answer here the answer will be easily findable with a search engine.

Undeleted

An answer of mine to Resources, references, or examples for logics with finitely many sentences was deleted via review.

May I kindly ask to reconsider this deletion. My answer relates to the observation that finite problems are always trivial in the context of computational complexity (see, e.g., the accepted answer here). The OP requested some clarification under my post, and I would have gladly given this clarification but my answer was already deleted then.

EDIT: It seems that I could undelete the question myself and provide the clarification. Is this the recommended way to proceed?

EDIT: I took the liberty of undeleting myself.

Re-opened.

Please reopen Less common probabilities and expected values related to the coupon collector problem. It is falsely closed as a duplicate. Though the question brought in the title is indeed very often it is not asked in the body of OP.

Particularly the question asks about the expected value of collected unique cards after a certain number of trials, not about the expected number of trials to collect a certain number of unique cards. Though the former question is probably have been already asked and answered here, it is certainly not that one which was linked as "original".

• What you say about not being a duplicate is true, but this is so because the OP asks multiple questions. By itself that is not a fatal flaw (the problems are closely related), but the Question provides no context. It appears to me to be a "pass through assignment". If you like the Question enough, perhaps leave a comment for the new user to provide context, or repost the problem with your own context. – hardmath Feb 10 at 16:46
• @hardmath OP indeed asks multiple questions. But none of the questions is asked or answered in the alleged "original". I would not complain if the question was closed because of "providing no context". This would stimulate the author to correct it. But the given link certainly will not help him or her to find the correct answers. – user Feb 10 at 16:52
• @hardmath That would be great. – user Feb 10 at 17:01
• After a bit of research I chose one of the coupon-collectors Questions that asks about the probability distribution aspect, and which not only has a decent Answer but also links to many other Questions of a similar nature. Of course the expected value problems are easier than working out the probability distributions (after $x$ cards bought), but the OP has done literally nothing to motivate writing out a new Answer. – hardmath Feb 10 at 23:57
• @hardmath The given link is of course very interesting but it does not address the asked questions, neither do the links inside. Though I agree that it can help to point out the direction (if the asker has a solid background). – user Feb 11 at 8:43

Re-opened.

A Basic Limit From Exponentials

I believe this is not a duplicate of How does one prove that $e$ exists? which was why it was closed.

The question from the first link asks why the limit $$\ \displaystyle\lim_{x \to 0} \frac{2^x-1}{x}\$$ exists. Whereas the question from the second link asks to prove that there exists a number $$a$$ such that $$\ \displaystyle\lim_{h \to 0} \frac{a^h - 1}{h} = 1.$$

Undeleted, deleted

Please undelete https://math.stackexchange.com/q/3998706/290189 as the question asker has self-deleted his/her own question a few hours after receiving an answer from a trusted user.

• Trusted users should be trusted not to answer copy-paste homework questions. – Gerry Myerson Jan 26 at 3:46

Reopened

I have also voted for closing the question as a duplicate but retracted the vote after the question was edited.

It is clear from the content of the edited question that its issue was a search for an error in the OP solution (and not for a correct way of solving the problem). In this sense it is certainly not a duplicate of the linked question. In any case as soon as the link to the alleged duplicate was given OP stated that (s)he is interested only in finding the own error.

I should admit that the linked question also started with an error (a different one) and this error was not addressed in any answer (but in one of the comments).

Quite generally I would assume that the most questions aimed on search of own error (or solution verification) cannot be treated as a duplicate.

• After you cast the reopen vote, the post automatically went into the reopen review queue. If you wait until the review complete, you might not need to post the request here (This is mentioned in the "guidelines" of this thread"). – Arctic Char Mar 24 at 15:03
• I agree and will next time follow the guidelines. Thank you for pointing my attention to this. – user Mar 24 at 15:07

Undeleted, redeleted

Please undelete https://math.stackexchange.com/q/3997519/290189 as the question asker has deleted his/her own question after receiving a well-written answer. That's not something we wish to see after spending effort on other's question.

• For future reference, "The asker deleted the question immediately after getting answers" is something that may be worth raising a flag over. – Xander Henderson Jan 25 at 23:00

Would it be possible to reopen: Counting how many items can be weight on a scale if we pick the weights optimally
It has an accepted answer and is not the same as the post that is linked to. Thank you for your time.

• I think it is sufficiently answered by the other post, even if it is not an exact duplicate. – Mike Earnest Mar 25 at 0:18

## Undeleted, reopened, reclosed (as duplicate)

Yesterday I posted this this question. When I checked it last night, it had the two sound-looking answers you see. I woke up today to find it had been not just closed but completely deleted. This seems to me completely preposterous. It's pretty clearly not a homework question, but a reasonably deep integral computation that I had no idea how to begin. I'd be happy to provide more "context" (1. unnecessary though that evidently was for the people who answered it, and 2. as if the identity isn't interesting in its own right) but the post is completely deleted and so I was given no opportunity to do so in anything like this site's notion of a timely manner. Is there some way I may be allowed to provide the all-important context in order to reopen the question so that I can at least reward the people who helped me?

• So you can just go to the deleted question (which you can get to from deleted recent questions in your profile) and copy the address from there an users with >10K rep can view it and possibly vote to undelete it. Posting an image here with no link makes anyone but a moderator unable to help you. – Matt Samuel Mar 31 at 23:37
• @MattSamuel I see, thanks. I've added the link – Tim kinsella Mar 31 at 23:56
• Can't you edit the deleted post? Asking for undeletion before improving your post (and not mentioning the fact that there's a linked duplicate in the comments) seems premature. – KReiser Apr 1 at 0:16
• still seems a bit of a shame that the very nice answers will be lost – Tim kinsella Apr 1 at 0:37
• just for the record though, it is as i thought -- i get the "This post has been deleted -- no more edits are allowed" when i try to edit it. @KReiser – Tim kinsella Apr 1 at 0:40
• The post has been undeleted (it is still closed. Perhaps it should be better closed as a duplicate) – Calvin Khor Apr 1 at 1:50
• Thanks you for improving the question - it is much better now. I voted to both close and delete this question at the time because it was simply the statement of a question without any context or effort or anything. I would have acted similarly if you had been a new user, but my actions were particularly heartfelt because you are not a new user, and instead have been here for almost 10 years and have picked up 5k rep. points. So you surely must have picked up on what is expected of a question by now... – user1729 Apr 1 at 10:00
• @user1729 I don’t know if this is the proper place to discuss this, but since you’ve made the same comment twice now I’ll respond by saying that I and a non-negligible minority of other users of the site don’t share your expectations that a post contain “context” or exhibitions of failed attempts when those things aren’t likely to help people answering it. My post is a good example. You say the post is now “much better,” but I think you’d be hard pressed to explain how what I’ve added about resolvents of Brownian motion would make it easier for someone to help me. – Tim kinsella Apr 1 at 10:34
• @Timkinsella Its not about someone being better able to help you, per se, although you have now given the book where they could look it up in (which is helpful when people misquote a problem, or the problem requires a result proven earlier in the book, etc.). There are other reasons for providing context too, including basic politeness, but also: We live in a world where the vast majority of exams are not in exam halls (for example, my uni has 24 hr take-home exams), so giving some context and providing some effort stops your question getting lumped in with the obvious cheaters. – user1729 Apr 1 at 10:43
• That is totally leaving aside your decision to vote to completely delete the question so soon after it was asked for the reason that it lacks context, a reason that calls for the OP to improve the post which he cannot do when the post is deleted @user1729 – Tim kinsella Apr 1 at 10:49
• @Timkinsella Sure. I would have been more lenient if you hadn't been here for almost 10 years with lots of rep. points. – user1729 Apr 1 at 11:04
• As one of the original close voters I should probably declare that I had the exact same thought process regarding voting to close. There so many questions that it's not effective for those that "stand on their own merits" to be vetted for quality by non-experts (e.g. experts in other fields), and the close voting is democratized. Writing for Math.SE is different from writing for a book. If you think there is a better (and scalable) alternative to separating the wheat from the chaff other than adding context, you should try to post a question on meta to persuade the majority. – Calvin Khor Apr 3 at 5:58
• @CalvinKhor If “wheat” = “questions that very probably didn’t come from a freshman calculus exam”, then I don’t really know what level of expertise you’re talking about. Behind this fixation on “context” and documentation of failed attempts I see no actual criteria for judging the quality of questions beyond an extremely crude correlation with the mere length of the post. – Tim kinsella Apr 4 at 6:03
• For instance, I wonder how a user might ask the same question I asked if it were merely posed to him, with no context, by a classmate? He has no context to offer you; are you going to believe he’s a curious student asking in good faith? Or are you going to fire off a passive aggressive comment about effort and expectations and delete his post? Seems like a tough choice if you’re philosophically opposed to actually thinking for a few moments about questions before you judge their quality. – Tim kinsella Apr 4 at 6:14
• @user1729 Frankly I wonder whether that’s true, and not just because you explicitly said the opposite in your first comment above. – Tim kinsella Apr 4 at 6:33

Please reopen Caching in Magma

The magma-cas is 100% mathematical software, and questions about it are not usually answered when posted on Stack Overflow. While the question is about how the software handles caching, MSE is the place to post this where it will most likely get an answer (and it has an answer; there are better answers that could be posted if it was not closed). It is also not a low-quality question that can be answered by pointing to the documentation.

[Edit:] MSE is where to post about these programs (magma, sage, gap) to get answers. The takeaway from the meta post linked in the comments is that no other SE site has a dedicated tag for the Magma CAS- in fact posts there are likely to be confused for a different computational package with the same name. There is no online forum anywhere. These posts are of interest to mathematicians and mathematicians only.

• To give the counter-argument, questions about implementation are explicitly noted as off-topic in the Help Center: "Algorithm implementation/design, computer simulation and modelling, etc. [might better be asked on] Stack Overflow". – Xander Henderson Feb 13 at 19:54
• @XanderHenderson That is not for the magma computer algebra system, it is for a different sortware package that is also called magma (though it looks like there are maybe a few random questions for the computer algebra system in there by mistake; they are told they are in the wrong place). – Morgan Rodgers Feb 13 at 19:56
• I've revised my comment. Also, note that this has come up before: math.meta.stackexchange.com/questions/22052/… – Xander Henderson Feb 13 at 20:02
• Also relevant: math.meta.stackexchange.com/questions/17119/… (takeaway: "being software used by mathematicians, Magma questions are on-topic here.") – Morgan Rodgers Feb 20 at 20:16
• The question has been deleted. – Gerry Myerson Mar 24 at 22:35
• I don't see how a question can be deleted "using high rep", Morgan. Questions can be deleted by a moderator acting alone, or automatically by the stackexchange software on meeting certain criteria, or by a sufficient number of users voting to delete, but not (to the best of my knowledge) by a single non-moderator user, no matter how many points that user has. – Gerry Myerson Mar 25 at 5:33
• @GerryMyerson Apparently I was mistaken, and questions can be deleted with 3 votes only, even with an upvoted accepted answer and a nonnegative score. I was under the impression they needed 5. – Morgan Rodgers Mar 25 at 5:51

Not sure if this belongs here, but Community accidentally deleted this question that I answered:

https://math.stackexchange.com/questions/3977648/how-can-i-find-the-mass-of-the-pencil-cylinder/3977750#3977750

(for +10k)

Does 'the binomial expansion of a negative prime number yield its equal and opposite trigonometric value'?

What is unclear or lacking in details about this please? I notice the close came AFTER I posted the screenshot.

closed for clarity/details (rather than off-topic). please help me improve details.

• I can't really see what to improve in that post. Unfortunately the question is complete : "make sense of something apparently mathematical said by somebody and written on a blackboard". It is not a bad question in terms of site rules, but the problem is it truly looks arbitrary to half the people who read it, so that results in a downvote for a question that is apparently of no use and insignificant. Anyway, voting to undelete, but I don't know what is going to be an answer at all, let alone a constructive one, from the discussion on the question. – Teresa Lisbon Jan 12 at 5:57