# Requests for Reopen & Undeletion Votes (volume 07/2018 - today)

The purpose of this thread is to help 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 was put on-hold pushes the question into reopen review queue, if the edit was done within 5 days of closure. So does a reopen vote. (If the review has already been finished, it is shown on the timeline of the question.) 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 once the request resulted in some action the information Reopened or Undeleted at the start. (If it the action is undone, add this too, like Reopened, reclosed.)

• Do not only post a request, like "request reopening of ". 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 in a away that takes the feedback the post received into account in a positive way 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 CRUDE is a reasonable place for such requests. The same guidelines apply there.

Earlier versions of this thread that served as a model:

Reopened

This is on the chopping block again: Is zero a prime number? The question was the subject of this meta discussion: How to prevent the loss of excellent answers to poor questions. which resulted in reopening.

(Disclosure, I have a solution on the question. I feel the question and solutions are worth fighting for, in this case.)

The reason this time for closure is "too broad", but it is far from obvious that this objection is valid. The OP asks three complete and answerable questions, two of which have answers elsewhere on the site. The remaining question became the focus of some of the answers, and there does not appear to duplicate with comparable content.

So for all intents and purposes, there is a single, clear question that seems rather likely for a layperson to ask, and there are good answers. There is nothing about the breadth of the question which inhibits solutions, as can be seen.

Furthermore, on the holistic side, after so many upvotes on the question and its solutions, and approaching now 30000 views, it seems that the post IS manifestly useful. So, I request your votes to re-open this.

• I agree that this rather should not be closed, especially after the improvement of the post. (Yes, the question still has some shortcomings, but I feel it is "good enough".) I tangentially got involved last time; but stopped short of taking action. I reopened it now. (This is less of a so-called unilateral action as it was 'nearly' reopened two weeks ago. ) – quid Jul 16 '18 at 17:42
• @quid Thank you for your attention to this! – rschwieb Jul 16 '18 at 18:28
• @quid I'm curious: my understanding was that closed questions were still viewable and not eligible for automatic deletion (assuming that the question is upvoted and has upvoted answers). Why is it inappropriate to close the question and leave a message to the effect of "This question has been preserved because of a good answer. It is never-the-less not a high quality question." For example, the lock message on this question. – Xander Henderson Jul 16 '18 at 19:04
• @XanderHenderson 'Why is it inappropriate to close the question and leave a message to the effect of "This question has been preserved because of a good answer. It is never-the-less not a high quality question.' Why do you use the indicative here? No one did that, as far as I know. In any case not recently. The question was reopened after a substantive edit, and then reclosed without comment, as 'too broad'. It also had a delete vote. Maybe more to the point, I would not consider it as inappropriate. But frankly given the edit I don't consider the question as all that bad. – quid Jul 16 '18 at 20:57
• Sure, it is a bit of a laundry list, and the last question is a bit strange, but in it's naive way even this seems like a genuine question. But it is also not unreasonably broad. Would it be asked now, I'd recommend to split it up, maybe. But this is not easy to fix now, and maybe not that important either. Maybe the combination of question even can be seen as hinting at the level at which the questions is asked. To only ask "is zero a number" might be ill-posed or underdefined, but in context I think it works. – quid Jul 16 '18 at 21:04
• Then there is also a community-aspect. Somebody actually put some non-trivial effort into improving this question, and the result is not that bad. If even this is not enough, at some point the line of argument that users should improve post they care about loses credibility, which leads to less improvements. @XanderHenderson – quid Jul 16 '18 at 21:10
• @quid I apologize---my original comment was poorly phrased, and likely not really related to this reopen request. A better phrasing might have been "In cases where there are really good answers to questions of marginal merit, (1) don't those answers automatically get preserved even if the question is closed? and (2) can such answers be protected? Since you seemed kind of ambivalent with respect to reopening (which I see now was an over-interpretation on my part), I was asking about an alternative. – Xander Henderson Jul 16 '18 at 23:38
• In any event, thank you for the feedback. I honestly do value it. :) – Xander Henderson Jul 16 '18 at 23:39

Reopened, Put on hold, deleted, undeleted, deleted, re-undeleted, re-deleted, undeleted again, deleted again, locked, unlocked and reopened

Please consider reopening What digits is the "number" $\infty$ composed of?. This question was closed as "not about mathematics". Obviously, this question is based on some misconceptions of what infinity is, but they are perfectly natural misconceptions for a layman and that hardly makes the question "not about mathematics". The question has a nice answer which clarifies the misconceptions and is a valuable addition to the site.

• I agree. Voted to reopen. – Brahadeesh Nov 13 '18 at 8:28
• I don't think having that question around helps us in building a useful math Wiki, which is what the founder of the site had in mind. – Jyrki Lahtonen Nov 22 '18 at 10:26
• Questions like this have really interesting and revealing answers. I'm thinking about padic numbers and infinitely long strings of digits depending on the base, but I feel like I'm denied my reopen vote by the vigilantes who co-ordinate their fast deletion vote, so minimally many users have the power to reinstate it. – user334732 Dec 1 '18 at 21:39
• I don't think the question is particularly bad, and not worth deleting. It addresses some common, layman misconceptions, and I don't think that is such a bad thing. (Maths suffers from a poor understanding at all levels of society - let us do what we can to help!) Also, the question is 4 years old. I favour keeping open older questions rather than judging them by todays standards. – user1729 Jan 30 at 19:58
• The question is currently undeleted but closed. The questioner seems aware that "infinity" might not actually be a number in the usual sense, but so far there's no answer explicitly saying how it differs from numbers. I would like it reopened to allow someone to post one. – timtfj Feb 5 at 12:32
• @timtfj: It is deleted again. Some discussion regarding the recent deletion can be found in the CRUDE chatroom. – user 170039 Feb 5 at 15:32
• @JyrkiLahtonen I disagree that the question is without use. I think a plausible-yet-naïve-question like this one has a lot of utility to resolve a misconception that others are probably going to have. I can't say I like this particular question, but I can say that I think it's dumb in this case to work so hard to delete it. (It seems to me that a useful wiki would want mechanisms to resolve misconceptions, anyway. Full disclosure: I don't really buy into math.se-as-a-wiki.) – rschwieb Feb 6 at 14:57

Closed, re-opened

Solve for $x^2 + 7x +1 = 3n(x^2 + x +1), n \in \Bbb{Z}$ My this question was put on hold as off-topic because it lacks context. It also gives a link to how I can add context. The link gave the following points

1. Include your work My response - I answered that question which I asked. I got a few hints from the comments which helped me. Should I give a summary of my solution it the question?
2. Motivation for question-
My response - I said in the details of the question that the original problem was a trigonometric equation which I solved but was stuck there.
3. Where did the problem come from? My response- it came from a book which is suppose to help me in my College entrance exam. But in this context it is really irrelevant and rather obvious.
4. give your background My response- I did give my background. I am a high school student who is self studying for college entrance exam.
5. reference My response- None exist.

I am not critising the one(many) who put my question on hold because nobody have to answer my question as this site is run by volunteers. I am just curious. How can I improve my question?

Reopened

The question A Proof of the Fundamental Theorem of Arithmetic was rightfully quickly closed as unclear, but the asker has since edited to clarify what they meant and what specific difficulty they had adapting the standard proofs to get what they want. It seems to me to be a perfectly reasonable question which is mostly clear (though a constraint like "not using integers or rational numbers" is inevitably going to be a little slippery).

Reopened

I edited the question Variable in upper bound of sum when it had 4 votes to close, and I also posted a rather detailed answer (which the OP accepted). It got "put on hold as unclear what you're asking" even though I think it's now quite clear and on-topic. Can the question be re-opened?

Reopened

The OP added an attempt to Determine the number of ordered triple $$(x, y, z)$$ of integer numbers (negatives and positives) satisfying $$|x| + |y| + |z| \le 6$$ in a comment to an answer while there was still only one close vote. I have moved that attempt to the question. I think that the question now meets the criteria for context.

• Doesn't the question now contain a complete solution to the problem? which makes it a pretty peculiar question? – Gerry Myerson Mar 28 at 21:53
• It gives context, which was why the question was closed. It doesn't really matter to me since I've already answered the question. Questions are not closed when the OP answers them, so I thought this one shouln't be closed for lack of context. Other answers might provide different insights. – robjohn Mar 28 at 23:29

Reopened, closed, reopened

I just came across this question: Derivative of Square Root Visual after failing a reopen review audit and I'm wondering why it's still closed: unclear what you're asking. I agree that the MathJax formatting isn't the best, but it is still readable.

The OP has actually shown what they've tried, and what they didn't get, so the reason for closure is beyond my understanding. I thus request to reopen the question.

I have now edited the question to make it look neater.

• Well it is definitely unclear what they are asking... One has to take roughly 10 mins to watch the youtube videos to see what they are trying to say (watching parts of 2:25 and 12:48 don't quite work, at least to me). – user99914 Jul 17 '18 at 10:32
• @JohnMa I think they meant 3:25, as it looks much more relevant? – TheSimpliFire Jul 17 '18 at 10:43
• They start the $x^2$ example at 2:35, and then to power rule (up to 10:30). Then they switch to $1/x$ (it seems this is the more relevant one). – user99914 Jul 17 '18 at 10:50
• This question is now reclosed as "off-topic". – Brahadeesh Apr 12 at 23:12
• Thanks for the update @Brahadeesh. It's now reopened. – TheSimpliFire Apr 13 at 9:33

Closed, re-opened

Please consider reopening What is wrong with this solution of find the least value of $\sec^6 x +\csc^6 x + \sec^6 x\csc^6 x$.

• This question is closed as a duplicate of this previous question by the same OP: Find the least value of $\sec^6 x +\csc^6 x + \sec^6 x\csc^6 x$ but the two questions are different. The closed question asks why a particular method of solution does not work, which is very different from the duplicate target.

• Perhaps relevant: the OP has also posted this question on Meta asking about the site policies on marking posts as duplicates (in general, and not pertaining to the reopening of this specific post).

• Also, OP has indicated that he/she no longer cares about the question, and in particular is not seeking reopening. – Gerry Myerson Apr 19 at 22:34
• @GerryMyerson True, but the post itself belongs to the community and I feel it is worth reopening, hence the request. – Brahadeesh Apr 20 at 0:53

Undeleted, reopened, closed

Minimum Elementary row/column transformations to find Inverse of given Matric

This question was definitely not up to site standards, but it had a couple of really cool answers, one that I had awarded a bounty to. I think it's worth undeleting for the answers alone.

• If the question is "definitely not up to site standards," then it really shouldn't be on the site. If you could edit it to bring its quality up, then that would be nice... but as it stands, I really oppose the undeletion or reopening of this. – T. Bongers May 17 at 4:02
• @T.Bongers That's why it probably should be closed, so it can be improved by the asker. I could edit it, but I don't want to hijack the asker's question any more than I have. I think it should not be deleted because it has illicited some interesting, unduplicated mathematical content that is, IMHO, worthy of the bounty awarded. – Theo Bendit May 17 at 4:06
• The asker had 28 days to improve the question before its closure, and another 5 before its deletion - they chose not to. Do you expect that to change if the question is undeleted? – T. Bongers May 17 at 4:46
• @T.Bongers no obviously no, Theo is not expecting the question to be improved but to show to the rest of the community the couple of really cool answers the 'bad' question has. – Isa May 17 at 4:49
• @T.Bongers I don't, no. I don't have any reasonable expectation the question to ever be re-opened. But in the interest of generating and collecting interesting mathematical content, I think it's worth keeping the question around. Are you saying I should edit it, replacing the asker's wording with my own, because the asker has abandoned it? – Theo Bendit May 17 at 4:55
• My opinion, Theo, is that if you can edit the question to bring it to where it can be undeleted, reopened, and stay open, then more power to you. – Gerry Myerson May 17 at 7:14
• Generally, it's not clear that the asker abandoned it. Anyway what I'd propose is that yes you edit it to something more readily comprehensible and detailed. I don't think there is a need to overdo this. For example, spell out the method the asker refers to, and rewrite the question so that no words are missing. Leave a friendly comment to OP saying that you found the question interesting and therefor fleshed it out a bit. If there is some problem with this approach, you can always ask your own version of the question and then ask for a merge, which would transfer the answers. – quid May 17 at 13:05
• @quid I might do the latter. I hijacked the asker's question to have a subtly different focus anyway. Once I've asked it, do I just flag a moderator's attention and request a merge? – Theo Bendit May 17 at 13:08
• Yes, a flag for mods is the way to go. However it'd be good to wait until the discussion has settled as once we merged it's near impossible to go back. – quid May 17 at 13:09

Undeleted

As per quid's advice, I would like to request that Number of real roots of an iterated quadratic: $$x^2-3/2$$ be undeleted. The question was self-deleted within a few minutes of my posting an answer which claimed that the conjecture of the question was false, so the reason for the deletion appears to be embarrassment. However, the question itself was an interesting one, as evidenced by more than 10 upvotes and 7 stars.

Reopened

I request a reopen of Are the corner hypercubera polytopes self-dual?. The question provides a v-definition of an infinite family of polytopes, and asks whether each member of this family is self-dual. (I don't see anything unclear about this question.) Other than being closed for being unclear, I haven't received feedback on this question.

I believe this Q&A provides the first known example of an infinite family of self-dual polytopes that is not a set of k-fold pyramids over a self-dual polytope.

• The post reads as a blog post, not a question. It needs to be vastly more concise, and I frankly don't think that MSE is a good site to ask questions like this; you would do better just talking to someone in the field. You got a bit of feedback in your last meta post. – T. Bongers Oct 1 '18 at 23:20
• Thanks for replying. I agree that a tag pertaining to just a question or two need not exist. As to the question, 1/3 of it is motivation, which I understand to be a requirement of MSE (I would just as soon leave it out). The answer is long because, while conceptually simple, the proof has a lot of tedious parts to it. – Dan Moore Oct 2 '18 at 0:35
• I've made my question more concise-it's now about 1160 characters & fits on my small Mac screen. My answer is about 18,000 characters. To analyze why it's so long, I counted the characters in eight distinct parts of the answer. Some parts are long because the thing to be proved requires a lot of words (wishing there was an elegant proof doesn't make it so). – Dan Moore Oct 2 '18 at 23:56
• Strictly speaking, the question was closed, not the answer. The Q&A is good because it sets forth the first example (ever in the history of mankind) of an infinite family of self-dual geometric polytopes (one for each dimension d $\ge$ 3) which aren't a set of k-fold pyramids over a self-dual polytope. – Dan Moore Oct 3 '18 at 0:00

Reopened

I would like to see the question "What is $$\nabla X$$ in Riemannian geometry?" re-opened. (I see from the timeline that the reopen queue has finished. In hindsight, I should have edited the title when I made the reopen vote.)

It appears it was marked as a duplicate of Gradient of a vector field?, seemingly because the short version of the question (and the old title, "What is $$\nabla X$$?") is very similar. But I would say that the rest of the question and the context (including tags) make it a question that necessitates an answer that would be inappropriate on the other question. "Gradient of a vector field?" has a tag and context of multivariable calculus, not Riemannian geometry.

Since "What is $$\nabla X$$ in Riemannian geometry?" doesn't yet have an accepted answer, I would like it re-opened so others can contribute.

Reopened

This question I asked was closed for lacking context. After context was added, the hold was never lifted, and eventually was closed.

$X,Y$ not homeomorphic if $X\backslash x$ is disconnected for all $x\in X$ but $Y\backslash y$ is connected for some $y\in Y$

Reopened, then closed as off topic, deleted

This question (does the existence of an lcm in a commutative ring imply the existence of the gcd of the two elements) was closed as a duplicate, pointing to this one (which shows inter alia that the existence of an lcm in a domain implies the existence of a gcd). In fact, I had done the same thing yesterday.

However, this is not a real duplicate. The question here is about rings, whereas the alleged duplicate is about domains. The proof there does not easily translate: for example, the first step of the proof in the question pointed to is to take $$m=\mathrm{lcm}(a,b)$$, let $$s$$ be such that $$ms=ab$$, write $$m=ar$$ and $$m=bt$$, and then claim that $$s=\gcd(a,b)$$. The first step is to show $$s$$ divides $$a$$, which it does by showing that $$(ab/m)*(m/b)=a$$. This is equivalent to saying that $$st=a$$; but I do not see how to conclude this in a ring (in a domain, multiplying through by $$b$$ and then cancelling will do it, but how do you do it here?).

As I had already closed it, and then re-opened, I can no longer vote to re-open on the page.

• Were it me, I would have voted to close the question for lack of context. There is zero context. Where did the question come from? What is the background of the asker? Why should anyone care about that question. It really isn't a very good question, and it probably should be closed. – Xander Henderson Sep 4 '18 at 3:48
• @XanderHenderson: That's valid, but the problem right now is that it points to a question claiming that it provides an answer when it does not. – Arturo Magidin Sep 4 '18 at 3:53

Closed, deleted, undeleted, deleted, undeleted, deleted, undeleted, reopened, closed, deleted, undeleted, deleted, undeleted, deleted, undeleted, reopened

This is being deleted repeatedly by the same people even though it has a great answer. There are several votes to reopen. I think it should be reopened because of the answer.

Cevians $AD$, $BE$, $CF$ are concurrent, as are cevians $DP$, $EQ$, $FR$; show that $AP$, $BQ$, $CR$ are concurrent

• By my standards the Question has sufficient context in respect of the OP's remark (in the original body of the Question) that we should try to apply Ceva's Theorem. – hardmath Jan 12 at 19:40

Undeleted and reopened

Please consider reopening the following question:

Evaluation of definite integrals with exponential integrand in Fourier sine transform

OP reduces the problem of finding Fourier sine transform to something that he/she does not know how to proceed further, which can be clearly justified as an attempt. I don't think we should close such post.

• You ask to reopen, but you write that we shouldn't delete. As you know, closing/reopening and deleting/undeleting are two different things. Presumably, you would like both to undelete and to reopen. May I suggest you edit your post to clarify. – Gerry Myerson Apr 27 at 0:22
• @Gerry Myerson: Sure. Edited. Thanks for mentioning that. – Jack Apr 27 at 1:46
• @Jack I noticed that after the comment by Gerry you edited the question to only request reopening, but I find this slightly confusing. Shouldn't the post request undeletion instead, since the question is currently deleted? – Brahadeesh Apr 30 at 15:29

Undeleted, redeleted，re-undeleted and locked (but for how long?)

About the Continuum Hypothesis asks a reasonable question that has been answered many times before. It was properly closed as a duplicate.

But it was then deleted, even though it had six upvoted answers with scores from 3 to 13. I think this was unnecessary and counterproductive.

I'd like to see it undeleted.

• "I think this was unnecessary and counterproductive." I don't see why it was counterproductive. Could you please elaborate? What I see is that there is quite questionable content in the question-post and the thread does not add anything that is not on the site elsewhere. Thus it is good that it is deleted. – quid May 17 at 20:11
• @quid is it that because are we running out of space in the site? :P – Isa May 17 at 23:02
• @Isa in a sense of memory, of course not, and deletion does not change anything. In the sense of giving space to good content over not so good one, in a way yes. We should get rid of not so good stuff so that better stuff gets more visibility. For the specific questions, there are just odd things in the question: "OK found out about Aleph numbers - so it isn't based on reality, but on some imaginary stuff. That's fine by me, my reality says integers < rational < real, but to each their own ..." Why should we disseminate this? – quid May 18 at 1:12
• @quid: Exactly, and that's not the only comment of this cranky sort by the asker, slashmais, who for example commented on hdhondt's answer saying "I think however that there is a major flaw in this reasoning and that I can demonstrate why the flaw occurs as well as how to resolve it, but it would be inappropriate for this site (elicit a discussion) - I would appreciate if you (or anyone else) can point me to a forum meant for such discussion.". – user21820 May 19 at 10:09
• I think the productive way forward is for any answerer, who thinks that his/her answer hasn't been expressed clearly enough on the (very excellent) earlier question by Steve314, to add an answer to that thread instead. – user21820 May 19 at 10:10
• In my opinion, the answer of mdp to the deleted question is so pedagogically excellent - better than any answer I've read so far on the other duplicates - that I can't understand the argument that its removal is good for the site. Yes, mdp (if she/he sees this) could cut-and past her/his answer to one of the other questions, but it would lose all its up votes, and therefore its visibility. Future readers would therefore be less likely to benefit from it. – Will Orrick May 19 at 15:58

Please consider undoing the duplicate votes here. The duplicate target is quite different as it asks for algorithms while this questions asks for easy ways to calculate determinant (so that careless errors are less likely to commit). The duplicate target is a poor question without context (though with some decent answers).

FYI: It failed the reopening review five times before, as of 3rd Sept. 2018.

• Two points: 1. did you ask the user that put it on hold as duplicate about it? 2. It seems that the answer on the dupe target includes the answer on the original question. // Personally I think the answer given on this question is pretty much besides the point. And the question is very localised. Long story short. I'd delete post. – quid Sep 3 '18 at 11:59
• @quid: I didn't (I thought this case is obviously wrong, and it had 4 reopen votes already). I agree that the question is localised and deletion is also a good choice. – user99914 Sep 3 '18 at 15:21

Reopened

The question was somewhat unclear when first asked, but was pinpointed down in comments. I also edited it providing a figure which helps to readily understand the situation.

The context provided by OP (by means of the "planified" picture) makes the source of confusion clear, and now that the problem itself is also clear, I think it fits the site well.

Reopened, then closed as duplicate.

It would be useful if this question can be reopened, so that it can be closed as a duplicate (see comments to post for more details).

• I am not sure there is much benefit in re-opening questions just to re-close them with alternative close reasons. This particular post really should be expanded significantly, if it is to be saved. Re-opening and re-closing will still probably lead to deletion. In particular, because it is a self-answered post, we can expect much higher standards than a post where the OP genuinely has a question. – Carl Mummert Oct 28 '18 at 1:07

Undeleted.

I nominate Is the numerical range of Identity operator convex? for undeletion because the question asker self-deleted her question shortly after receiving an answer from a high-rep user. That's an abuse of the system.

Reopened.

This recent Question asks about a variant of the Secretary Problem which as far as I can tell has not been previously answered here.

I mistakenly proposed to close as a duplicate of the classic Secretary Problem, but this variant treats as equally successful the choice of either the best or the second-best candidate. Please consider adding your vote to reopen to mine.

[NB: I edited the title of the post to clarify that this is not identical to the earlier Question, and I discuss in the comments there what little Math.SE discussion there had been on this variant (without supplying its literature references).]

• I've edited the question to refine the formatting and grammar a bit, and to use more gender neutral language. I don't think that the question is all that great (it is a problem statement question with a largely nonsensical "attempt"), but I agree that it isn't a duplicate question, and it is somewhat better than much of the stuff that gets posted. In any event, the question is now open again. – Xander Henderson Nov 27 '18 at 2:27

Undeleted, closed, deleted, re-undeleted, reopened

I nominate How to use derivatives to prove that $f(x)=2\cos^2\left(\frac{\pi }{4}-\frac{x}{2}\right)-\sin \left(x\right)=1$? for undeletion since OP has self-deleted his/her question after receiving an answer. This is unacceptable on Math.SE.

• It's better to write self-contained posts. In the current case for the moment there was no big risk, but it's still not ideal. – quid Nov 8 '18 at 19:42
• @quid Thanks for your intervention. I'll correct this now. – GNUSupporter 8964民主女神 地下教會 Nov 8 '18 at 19:44
• I don't understand why this question was closed and deleted by users. It is not unclear what they're asking. (It may not be true, but it is certainly clear!) – user1729 Feb 5 at 11:28
• @user1729 Some users don't like wrong info in the question. They have standards so high that $D(\sin x)$ and the RHS of $f'(x)$ doesn't please them. It's possible that they used their power to get rid of this question. – GNUSupporter 8964民主女神 地下教會 Feb 5 at 11:37
• It's definitely not unclear—the questioner gives the problem, shows what they did, and asks what's wrong with it. I think it could do with an additional answer which makes crystal clear what the error was and how the (interesting!) technique works, and reopening would allow someone to post that. – timtfj Feb 5 at 12:06
• @timtfj It's now reopened. – GNUSupporter 8964民主女神 地下教會 Feb 5 at 16:04
• @GNUSupporter8964民主女神地下教會 At least it's clear that their expectations could never rise to match the size of your assumptions... – Lord_Farin Feb 6 at 17:34

Undeleted, then deleted again, then undeleted again, then reopened, then closed again, then reopened again

Please undelete Compare $\arcsin (1)$ and $\tan (1)$ because OP has made an observation $$\sin(\tan1)\leq1$$ in order to compare the two quantities in the question title. This question has

• 3 $$\star$$;
• 1 Undelete vote remaining to save this question.

Reopened

Please reopen this this question. One user @lulu stated the question was clear but it is still closed.

If the question is unclear, state why?

This answer from 7 months ago was apparently deleted by Community as spam or offensive yesterday. I don't see how it could be offensive, and such an answer to a question tagged is surely not spam. Why would someone flag this answer?

And in any case, it's certainly not a great example for a review audit...

• I failed a similar review audit today... – YuiTo Cheng Apr 25 at 16:16
• Same answerer, posted the day after, deleted more or less at the same time with a link to the same site and in both cases the post is identical to the linked review... It's weirder than I thought. – Arnaud D. Apr 25 at 16:23
• I think only moderators can undelete a post deleted by Community, right? (it's even locked in this case) – YuiTo Cheng Apr 25 at 16:28
• According to this answer and the linked Meta answer, this is indeed the case for posts deleted as spam (in fact they are locked) but not the others. – Arnaud D. Apr 25 at 16:36
• Are spam flags handled by Community? – YuiTo Cheng Apr 25 at 16:56
• Again?! (notice the answerer's account has been deleted, which still exists yesterday) – YuiTo Cheng Apr 26 at 2:08
• There is also this one, though I don't know if it has been used as an audit. The same user also has a deleted answer on MO apparently, though I don't have the rep to see it. I understand the deletions a bit more now... – Arnaud D. Apr 26 at 5:49
• I've added a post about these audits in this thread. – Arnaud D. Apr 26 at 6:01

Reopened

This meta question has been closed as a duplicate:

However, it is not a duplicate. The older question is about deleting questions with answers, which is a more general question. (Indeed, it starts with the phrase "A few deays ago I posted an answer...") The newer question is about a special case, and which deserves a separate discussion. In particular, the newer question states [emphasis not mine!]:

Recently...quite a few old questions with good answers are being closed and deleted...I do not see any merit for closing such old questions: who the heck do we really expect to come back and "provide additional context" for a question that was asked two or even six years ago?

Of course, you may believe that this question is not worthy of a separate discussion. That's fine, but I believe the correct way of expressing this opinion is the answer the question saying so, and linking back to the older question.

• Well, it would help if the poster(s) of new meta discussions would take earlier ones into account more systematically. But, yeah, I'll reopen it. If people want to discuss again, that's fine to a point. . – quid Apr 29 at 8:29
• @quid My point is that the word again is not relevant. Its an essentially new discussion, not covered in the older post. Do you not agree? (It would be nice to clarify the reopening reason first, for posterity's sake.) – user1729 Apr 29 at 8:38
• Yes, I'll leave a comment. The issue with these things is that even if the question is technically different, the discussion is often not focused enough. I know that you noted that with the other answer there. – quid Apr 29 at 8:46
• @quid Thanks. Incidentally, is it possible to delete the other answer, the one I commented on? (Or does that take moderation too far?! I flagged it as "not an answer" a wee while ago.) – user1729 Apr 29 at 8:52
• Well, depends who you ask. I prefer not to delete it, but you could request it in aa comment. – quid Apr 29 at 8:55

Undeleted, and closed as off-topic, re-deleted

Please consider undeleting the following post: What is the area of the shaded region.

Considering the high quality of several answers to the question, I do not think we should delete the post.

Undeleted

I nominate Factorising the ideal $(14)$ in $\mathbb{Q}(\sqrt{-10})$ into a product of prime ideals. for undeletion since the question asker has self-deleted his/her own question after receiving an answer. This is unfair the answerer who spent time and effort writing the answer, which deserves evaluation from the community.

Undeleted, then closed and deleted

I think there's a consensus that we undelete questions when they are deleted by the user who posted them after someone else has posted an answer (see, for example, the comment here: https://math.stackexchange.com/questions/2759560/extending-the-triangle-inequality#comment5694741_2759560). In accordance with that consensus, I propose undeletion of https://math.stackexchange.com/questions/2840649/solutions-to-sum-j-ok-r-j23r-j2-equiv-0-mod-p

Now I'll own up that I'm the one who posted the answer to the question. My answer was exceedingly terse, and came out of a review with the note, "This does not provide an answer to the question (and so on, and so forth)." But it does provide an answer. The question was to prove or disprove that there are no solutions to a certain equation (congruence, actually, but never mind), and my answer gave a solution.

• Is this actually a consensus? – Did Jul 23 '18 at 12:30
• @Did, if you look at the previous edition of this thread, you'll find that in April-May, GNU Supporter posted 4 requests for undeletion, all on the grounds that OP had deleted a question after receiving an answer, and all four questions were undeleted. – Gerry Myerson Jul 23 '18 at 12:51
• Yes, and?   – Did Jul 23 '18 at 18:11
• @Did For what it's worth, I have the same impression about the consensus. Preventing an asker from covering up their own question seems to be something the community values, even if it's closed later. – T. Bongers Jul 23 '18 at 18:35
• @T.Bongers (and also Gerry Myerson): I think that there is a moderate consensus that it is bad form to ask a question, get an answer, then delete the question. It belies an ignorance of the functioning of the site (i.e. questions are supposed to be helpful to everyone, not just the one person asking the question). However, in this particular case, the question is of pretty low quality, and should be closed and deleted (in my opinion). It seems like a waste of resources to have opened it back up again... – Xander Henderson Jul 23 '18 at 19:00
• For what it's worth, I have expanded my answer to the question on main. – Gerry Myerson Jul 24 '18 at 0:34
• "For what it's worth, I have expanded my answer to the question on main." On this topic, my understanding is that the consensus is that a good (or even great) answer is not really enough to justify keeping a poor question around. This and this are relevant. – Xander Henderson Jul 24 '18 at 13:27
• @Xander, the highest-voted answers and comments on your first link hardly support your understanding. The second link, even there there is considerable support for not deleting questions with good answers. I'm not convinced there is, was, or ever will be a consensus on this issue. A majority, maybe, but no consensus. – Gerry Myerson Jul 24 '18 at 21:31
• @GerryMyerson I think you and I must be reading very different answers. In answer to the question of whether bad questions with good answers should be preserved, my reading of the top three answers ((1), (2), (3)) suggest that it might be worth protecting a poor question if it hosts an excellent answer. – Xander Henderson Jul 24 '18 at 22:54
• On the question of upvoting poor questions with good answers, the top voted answer is this one, essentially "I don't do it, but there could be an argument in favor of it." The second answer is similar, with the idea being that a good answer should be preserved if it might be helpful for others in the future. – Xander Henderson Jul 24 '18 at 22:55
• In both cases, it seems clear to me that the consensus is that it might be reasonable to preserve a poor question if it attracted a really good, useful, generally helpful answer. Again, a good answer (or possibly even a great answer) is not, by itself, enough to preserve a poor question. – Xander Henderson Jul 24 '18 at 22:58
• Finally, I note that I made my initial comment in response to your assertion that you have improved your answer. Are you further asserting that the improvements created something that is of such lasting value that it will be beneficial beyond asking that poor question? Despite the fact that this question and answer have been the topic of discussion here for a couple of days, your answer has not attracted any upvotes... – Xander Henderson Jul 24 '18 at 22:59
• @Xander, I'm not in it for the upvotes. I objected to a user posting a question and then deleting it when it got an answer, as I agree with a moderator that such an action is an abuse of the site. Once the question was undeleted, I took the opportunity to improve my answer, in response to a comment from another user. What's wrong with that? I'm not asserting anything about the lasting value of the question or the answer, other than the answer being fuller now than it was. The answer may help someone coming along who is interested in sums of two squares modulo a prime. Fire away. – Gerry Myerson Jul 24 '18 at 23:30
• @GerryMyerson: it isn't pleasant to see one's own answer deleted, but in this case the question is clearly not up to many users' standards, so I think it is not surprising to see it deleted. At this point, the question is no longer deleted by the OP, but by several other users. – Carl Mummert Aug 5 '18 at 21:06
• @Carl, it isn't pleasant to see any answer with nonzero mathematical content deleted. More to the point, I would not have put the question up for undeletion, had it been deleted by votes of users. My objection was to OP abusing the site by deleting the question after getting an answer. I thought that was clear. – Gerry Myerson Aug 5 '18 at 23:09

## protected by Community♦Oct 1 '18 at 14:49

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