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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:

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128 Answers 128

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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.

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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).]

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    $\begingroup$ 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. $\endgroup$ – Xander Henderson Nov 27 '18 at 2:27
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Undeleted

I nominate Is the Balazard-Saias-Yor integral non-positive? for un-deletion and re-opening. Being self-deleted by a deleted user, it has a score of +1 and two stars. The topic adds value to the site and the question asker has put effort in the post.

Currently, only one undelete vote is needed to undelete this question. I hope the two users who starred this question can see their favorite question re-opened.

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    $\begingroup$ It should be noted that "stars" do not necessarily indicate that a user finds the question useful or up to the standards of the site. Many users use stars to keep track of questions with which they have interacted, and desire to return to at some point. For example, I sometimes star questions which lack context or otherwise fail to meet the standards of this site. After downvoting, leaving a comment, and/or voting to close, I will star the post so that I can return to it a few days later to see if it has been improved. If it has, I'll retract my downvote and/or close vote. $\endgroup$ – Xander Henderson Feb 4 at 17:02
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    $\begingroup$ I'm not saying that this is the case here; I just want to point out that "stars" should not be taken as a sign of quality vis-a-vis undeletion votes. $\endgroup$ – Xander Henderson Feb 4 at 17:03
  • $\begingroup$ @XanderHenderson Thx for comments. Noted. $\endgroup$ – GNUSupporter 8964民主女神 地下教會 Feb 5 at 1:27
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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.

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  • $\begingroup$ 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. $\endgroup$ – quid Nov 8 '18 at 19:42
  • $\begingroup$ @quid Thanks for your intervention. I'll correct this now. $\endgroup$ – GNUSupporter 8964民主女神 地下教會 Nov 8 '18 at 19:44
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    $\begingroup$ 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!) $\endgroup$ – user1729 Feb 5 at 11:28
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    $\begingroup$ @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. $\endgroup$ – GNUSupporter 8964民主女神 地下教會 Feb 5 at 11:37
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    $\begingroup$ 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. $\endgroup$ – timtfj Feb 5 at 12:06
  • $\begingroup$ @timtfj It's now reopened. $\endgroup$ – GNUSupporter 8964民主女神 地下教會 Feb 5 at 16:04
  • $\begingroup$ @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... $\endgroup$ – Lord_Farin Feb 6 at 17:34
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Undeleted and merged with duplicate

I would like to see the question "Finding sum to infinity" undeleted. The OP says that they "tried using the Taylor series for $e^x$ but couldn’t figure out how to manipulate it to get the above expression", which seems reasonable. Moreover:

  1. The question is a duplicate and is closed as such. It is not standard practice to delete duplicates (see here).
  2. The question itself is on +5 (+6/-1), and one of the answers is on +12.
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    $\begingroup$ I don't get the argument. What is the value of keeping that question on the site? $\endgroup$ – quid Feb 15 at 19:00
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    $\begingroup$ I didn't realiize that "it is standard practice to not delete duplicates." Cite? $\endgroup$ – Gerry Myerson Feb 16 at 4:06
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    $\begingroup$ @GerryMyerson I also had entertained to comment on that. What arguably is true is that "it is not standard practice to delete duplicates", which of course is not quite the same. $\endgroup$ – quid Feb 16 at 12:14
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    $\begingroup$ @Gerry What I meant was "a question should not be deleted simply because it is a duplicate" (so I've edited the post to quid's sentence). This was discussed here. $\endgroup$ – user1729 Feb 18 at 11:28
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Merged

Please Consider undeleting the following question:

https://math.stackexchange.com/questions/3203711/what-are-the-steps-to-finding-int-01-frac-ln1-x-lnxx-dx

Of course, this one is a strict duplicate of the one for it was closed. However, regarding the fact that the answers to this question at all are quite spread I would like to draw attention to my own answer given here collecting some of the possible ways to evaluate this integral within one post.

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    $\begingroup$ Would it make sense to merge the thread with the duplicate target? $\endgroup$ – quid May 4 at 10:11
  • $\begingroup$ @quid That might a better way than undeleting the question, indeed. I'm ashamed to ask, but what exactly does it mean to merge a thread with another one? $\endgroup$ – mrtaurho May 4 at 10:13
  • $\begingroup$ It means that the answers will be moved to the other thread (and deleted on the original one). The Q can be preserved (like a duplicate) or not. $\endgroup$ – quid May 4 at 10:16
  • $\begingroup$ @quid That sounds pretty good. Shall I do this, at least with my own answer, by myself or do I have to request for this somewhere? $\endgroup$ – mrtaurho May 4 at 10:18
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    $\begingroup$ That's something only moderators can do. (Of course you could simply repost your answer on the dupe too, but that would not be merge.) I'll just go ahead and do it now. $\endgroup$ – quid May 4 at 10:23
  • $\begingroup$ @quid Thank you for your time! $\endgroup$ – mrtaurho May 4 at 10:24
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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.

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Reopened, closed again as duplicate

I nominate reopening Non-negative integer solution for $ax + by = c$. The OP updated the question with what I consider to be sufficient context after the first close vote, but before the final one. As I thought the updated text then made it an appropriate question, I provided an answer. After I discovered it was closed, I flagged it for reopening, but this was declined. FYI, the full timeline is here. Please check this question to see if it should be reopened. Thanks.

Update: As explained in the comments, the question is really a duplicate. It's now closed again for what I consider an appropriate reason, i.e., as a duplicate.

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    $\begingroup$ It's a duplicate of math.stackexchange.com/questions/490602/… and probably several others. If it's reopened, it should immediately be closed as a duplicate. $\endgroup$ – Gerry Myerson May 28 at 6:37
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    $\begingroup$ @GerryMyerson I appreciate your feedback. Since it's a duplicate, I don't have any problem with closing it as such (if it's first reopened), and will even vote to do so. $\endgroup$ – John Omielan May 28 at 6:44
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    $\begingroup$ @GerryMyerson I just gave the last vote to reopen the question. To follow through on what I stated above, I then tried to vote to close as a duplicate. However, because I gave a vote to close on April 18 and then retracted it (due to the OP giving more context so I thought it shouldn't close), the system won't let me vote to close it again, even though it's gone through a close/reopen cycle. As such, perhaps you may wish to start the process of closing it now as a duplicate. Thanks. $\endgroup$ – John Omielan Jun 1 at 3:09
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Reopened

Please consider reopening Does knowing the surface area of all faces uniquely determine a tetrahedron?. This is a very natural and self-motivating question that does not need any additional context, and it's gotten several great answers.

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Reopened

Please consider reopening this post, suitably narrowed since originally closed as "too broad":

Book recommendation... Linear Programming for self-study

I don't believe there has been another such request, and under my pestering the OP has provided context for what sort of self-study they've previously undertaken.

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Reopened

Please consider reopening Does non-uniqueness of solution to 1st order ODE implies the existence of infinitely many solutions?.

This is an interesting question about a not so famous result in ODE. The answers points to the correct reference. I've edited the question to include more context.

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    $\begingroup$ I agree it's an interesting question, and the updated text now has enough context, so I initiated reopening it. $\endgroup$ – John Omielan Jun 18 at 16:36
  • $\begingroup$ @JohnOmielan, if you care, please consider also editing the answer there (to rollback to edit 1). Now that the post is reopened, there is no need for that comment. I tried to edit myself, but the suggested edit got rejected $\endgroup$ – Arctic Char Jun 19 at 19:20
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    $\begingroup$ I agree the comment there regarding it being closed is no longer pertinent, so I did rollback of the edit. $\endgroup$ – John Omielan Jun 19 at 19:26
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Undeleted (and edited the duplicate target)


Please undelete this post:

Three coins are tossed. If one of them shows a tails, what is the probability that all three coins show tails?

This question was marked as a duplicate to another question (created 2014) that was closed and deleted (2018).

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    $\begingroup$ It seems it took 9 votes to delete this question. I suppose that's because it had 30 upvotes? Anyway, currently it has 7 undelete votes. Does it need 9 to undelete? $\endgroup$ – Gerry Myerson Jul 5 at 5:52
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Undeleted, reopened

Please consider undeleting and reopening this post:

How does one prove the inequality $1+|x|\le (1+|y|)(1+|x-y|)$?

OP clearly indicated the context of his/her question: it is from a proof in Wolff's lecture notes on harmonic analysis.

[Added upon request: this post has also been edited into a (more) decent one.]

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    $\begingroup$ If you edit a post significantly indicate so in the request. I have no problem with it by itself, but since such actions are quite frequently overlooked by observers it can lead to the false impression that a relatively decent post was deleted. $\endgroup$ – quid Jul 8 at 14:07
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    $\begingroup$ @quid If someone else (not OP) edits OP's question to make the question 'fit' on MSE, then does the question gets reopened or undeleted always? $\endgroup$ – user486983 Aug 9 at 18:48
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    $\begingroup$ I said different by OP because sometimes the question is old, say 2015, and OP hasn't visit MSE since 2015. $\endgroup$ – user486983 Aug 9 at 18:51
  • $\begingroup$ @Isa I'd say yes for the most part (although what 'fit' mean of course leaves room for interpretation). That said, some users do not like the practice, thus there can also be push back. But in abstract and as a general principle (there can be exceptions in special cases) if a question is a good fit for math.se we usually keep it around no matter how it arrived in this state.// If you want to discuss this in more detail please open a separate thread. $\endgroup$ – quid Aug 9 at 19:32
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Reopened

Prove: there exists 3 sets: $A, B, C \subseteq \mathbb{N}$ such that: $A\cap B\cap C =\emptyset$ and $|A|=|B|=|C|=\aleph_0$?

Please consider reopening my question as I've edited it in order to explain the full context of it.

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    $\begingroup$ The current status is only to be added after a change occurred. In any case it should always be the current status of the post not the requested action. $\endgroup$ – quid Aug 15 at 13:19
  • $\begingroup$ I understand. thank you for the help $\endgroup$ – Jneven Aug 15 at 13:20
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Undeleted, reopened, closed as duplicate

Please consider undeleting this well-received (33 net upvotes) question under the tag of probability: Probability of drawing the Jack of Hearts?

There are useful discussion and several good answers, one of which has 77 upvotes.

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  • $\begingroup$ The question was originally closed as "off-topic: lacking context" (which, in my opinion, was not unreasonable). It is, however, also a duplicate of other questions, as indicated by the comments. If it is to remain on the site, it should be properly linked via a dupe closure. $\endgroup$ – Xander Henderson Aug 19 at 17:38
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    $\begingroup$ At most "similar" or "related". Not a duplicate. $\endgroup$ – Jack Aug 19 at 17:54
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    $\begingroup$ I'm sorry, but what? The question above asks us to determine the probability of drawing a Jack from a deck of cards from which an unknown card has been removed. One of the two questions in the dupe target asks for the probability of drawing an Ace from a deck of cards from which an unknown card has been removed. These are precisely the same question, and answers to the older question completely answer the newer question! How is this not a duplicate? $\endgroup$ – Xander Henderson Aug 19 at 18:32
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    $\begingroup$ Mr. Henderson, I have a very narrow definition of "duplicate" from yours. No need to be sorry. And of course you do have the right to vote it as a duplicate. $\endgroup$ – Jack Aug 19 at 18:34
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    $\begingroup$ I marked it as a dupe. That said @Xander I think the difference is slightly larger than you make it look. This question is about one specific card (a jack of hearts), while the dupe is about a group of cards (an ace). I still think that is a duplicate. // Since the comment on main got auto-deleted I'll add that two users other than me had mention it as a dupe. Thus, it was at least a trilateral closure. :-) $\endgroup$ – quid Aug 19 at 18:54
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    $\begingroup$ @quid Indeed, I had missed that. That said, as you note, the distinction is not fundamental. Thank you for handling it. $\endgroup$ – Xander Henderson Aug 19 at 19:39
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Reopened


The question Problem with sum of projections was incorrectly marked as a duplicate of Orthogonal projections with $\sum P_i =I$, proving that $i\ne j \Rightarrow P_{j}P_{i}=0$. The latter question has the additional hypothesis that the projections are self-adjoint (i.e., orthogonal projections) which allows for some rather different proof methods. Indeed, none of the four answers to the second question solve the first question.

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Deleted, undeleted, deleted, undeleted, deleted, undeleted, deleted, undeleted and reopened

unfortunately the question I asked Why is the zero polynomial the only one to have infinite roots? was put on hold as off-topic first and then closed. I edited it much for it to be reopened but it wasn't opened. I apologise if it was off-topic to you, but I edited it. If it being off topic yet, kindly suggest improvements or reopen it.

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    $\begingroup$ Please include a link to the question. $\endgroup$ – quid Feb 3 at 14:54
  • $\begingroup$ its humble request $\endgroup$ – user629353 Feb 3 at 14:56
  • $\begingroup$ why you deleted that $\endgroup$ – user629353 Feb 3 at 14:58
  • $\begingroup$ @quid couldn't you suggest edits $\endgroup$ – user629353 Feb 3 at 15:03
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    $\begingroup$ "couldn't you suggest edits " What do you mean? How am I supposed to know which question you mean? $\endgroup$ – quid Feb 3 at 15:05
  • $\begingroup$ @quid the link of which i have given above $\endgroup$ – user629353 Feb 3 at 15:09
  • $\begingroup$ I misunderstood what you meant. I did not delete you question. At the moment I do not plan to get involved. $\endgroup$ – quid Feb 3 at 15:46
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    $\begingroup$ Two posts here about the same question. Are we supposed to expect some more any time soon? $\endgroup$ – Did Feb 3 at 21:39
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    $\begingroup$ @Did, the first post was about closure, the second, deletion. Unless there is some action more severe than deletion, I'd guess there won't be any more posts about the question. $\endgroup$ – Gerry Myerson Feb 3 at 21:52
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    $\begingroup$ I have flagged the question on main to ask the moderators to let the community make the decision. $\endgroup$ – Gerry Myerson Feb 5 at 11:48
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    $\begingroup$ The main problems with the question seem to be that (i) the questioner is confused, and (ii) it's tricky to answer in a way that properly addresses the confusion. The first seems a good reason to ask the question, and the second suggests that good answers will be thoroughly explanatory and therefore of high value. $\endgroup$ – timtfj Feb 5 at 16:05
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Reopened

Please re-open this question which is put on hold:

Understanding De/Suspension $\Sigma^{-1}(\Sigma{X})\neq X$

It was said that "unclear what you're asking" and people do not know the def of de-suspension.

However, the suspension is introduced earlier in the cited question:

The suspension (topology) and elementary examples

While the desuspension is also quoted/linked to the Wikipedia (withe refs given by Wiki). I also include a new note: "The desuspension is arguably firstly introduced in the cited text mentioned in H. R. Margolis (1983). Spectra and the Steenrod Algebra. North-Holland. p. 454." And the ref cited.

Follow people's comments, I modify to also ask the basic definitions:

Question: How do we define desuspension exactly? (Please see the comments below, people complain about the meanings of desuspension in Wikipedia is useless).

Are we able to have the desuspension acting on the topological space as the suspension does? Or do we only have the desuspension act on the spectra but not the space?

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Reopened

Please consider reopening this. It was closed originally as missing context. The OP provided some context in the comment and I have added a little bit more. Hope it is okay now.

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  • $\begingroup$ Wow, this question was through reopen review queue already four times. It makes me wonder what is the record. $\endgroup$ – Martin Sleziak Sep 1 '18 at 1:04
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    $\begingroup$ I think it just how difficult it is to reopen a post using only the review queue. @MartinSleziak $\endgroup$ – user99914 Sep 1 '18 at 13:00
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    $\begingroup$ This one has 5 and is still closed. $\endgroup$ – user99914 Sep 1 '18 at 13:01
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Reopened

Please consider reopening the question A functional equation of a matrix that is placed On Hold. I have added my attempt at the cracking the problem if the lack of it was the reason for placing it on hold. The question itself is technically perfectly sound.

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    $\begingroup$ You should have just edited your previous answer, and not added another "answer." $\endgroup$ – Joel Reyes Noche Sep 25 '18 at 7:07
  • $\begingroup$ @JoelReyesNoche: What do you mean? "Answer" to my question that I linked to? I did not post an answer to my own question. $\endgroup$ – Hans Sep 25 '18 at 8:18
  • $\begingroup$ No, answer(s) on the present meta page, there should not be two for a single post on main. $\endgroup$ – Did Sep 25 '18 at 9:31
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    $\begingroup$ I have removed the second post, since this one has been edited to indicate the reopening. I've also edited and deleted/undeleted, so whomever downvoted can undo their vote. $\endgroup$ – Asaf Karagila Sep 25 '18 at 9:56
  • $\begingroup$ @AsafKaragila: Oh, sorry. I did not know the first request was posted as I remembered closing the page rather than posting the "answer" as I needed to leave in a hurry earlier. I posted the second request thinking that the first request was not posted. This is the first time I post in the meta question site. $\endgroup$ – Hans Sep 25 '18 at 10:59
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    $\begingroup$ Why this post says "reopened" when the linked question is still on hold at the moment? $\endgroup$ – Martin Sleziak Sep 25 '18 at 12:31
  • $\begingroup$ @Martin, seems to have been a mistake, which I have rectified. $\endgroup$ – Gerry Myerson Sep 25 '18 at 12:37
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    $\begingroup$ The thing that is missing in the current version of the question, more than work, is the source of the problem. Why do we expect it is true in the first place? $\endgroup$ – Carl Mummert Sep 25 '18 at 19:32
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Undeleted, redeleted, undeleted again, reopened

Statements that look obviously false but cannot be disproved. is at $+15$, and has answers at $+7,+10,+14,+20,+21,+8$, and $+15$. Please consider voting to undelete. [In the interests of transparency, I note that the $+15$ answer is mine.]

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    $\begingroup$ I agree that the question is highly upvoted and has highly upvoted answers. That does not make it an appropriate question for MSE. With regard to what is on-topic, it isn't a problem or puzzle, and I see no clear indication that there is a particular topic that needs to be clarified. With respect to what not to ask, the question seems designed to engender discussion, not to seek explanation. $\endgroup$ – Xander Henderson Sep 27 '18 at 16:35
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    $\begingroup$ For the benefit of the people who cannot see deleted questions, I'll add that this MO question is mentioned in comments: The most outrageous (or ridiculous) conjectures in mathematics. (Even if this one does not get undeleted, the linked MO post might be interesting for people who would consider Statements that look obviously false but cannot be disproved interesting.) $\endgroup$ – Martin Sleziak Sep 28 '18 at 8:42
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    $\begingroup$ @XanderHenderson Just curious, what would you then consider as on-topic for the soft-question and big-list tags? $\endgroup$ – dxiv Oct 4 '18 at 5:51
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    $\begingroup$ Surely we have better things to do that relitigate this post over and over again, and remove the collective efforts of 16 people. I see no harm from the existence of this post, except for the ruffled feathers of people who are inclined to overmoderation. $\endgroup$ – user296602 Oct 4 '18 at 22:13
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    $\begingroup$ In my opinion, if some want content and others do not then it should stay. The veto should be over removal rather than the converse. I will never understand why it's so important to wreck somebody else's party. $\endgroup$ – samerivertwice Dec 1 '18 at 18:22
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Undeleted

The deleted answer for Show that there does not exist a unique stationary distribution. should be undeleted.

The question is about "existence of unique stationary measure", and the answer is concise and to-the-point.

"$(1,0,0,...,0)$ and $(0,0,...0,1)$ are two invariant distributions so uniqueness fails."

The existing answer shares the same idea with the deleted one, and it has passed a Low Quality Review.

(Edit: comment removed)

The deleted answer attracted an comment from a high-rep user during another Low Quality Review. However, by appealing to his/her tag score for the relevant tags (, , , , , etc) (and the contributing posts) and comparing them with those of the answerer, you'll have a better idea about their contributions to the site in those areas.

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    $\begingroup$ Oddly, the deleted answer was deleted, not through review, but by its owner. $\endgroup$ – Gerry Myerson Oct 12 '18 at 11:51
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    $\begingroup$ You could ping the author on another of his posts, but I generally oppose undeleting a self-deleted post. $\endgroup$ – user296602 Oct 12 '18 at 15:14
  • $\begingroup$ The author has commented on the other answer, so he can be pinged there if necessary. This is an odd situation. $\endgroup$ – Arnaud D. Oct 12 '18 at 17:34
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    $\begingroup$ Thanks for advice. I did ping the author. He can undelete this anytime he wishes. I ponder whether CRUDE is healthy, when some of its active users vote to delete short answers outside their familiar tags regardless of the quality of the answer. This isolated example shows that its malfunctioning in terms of quality control. $\endgroup$ – GNUSupporter 8964民主女神 地下教會 Oct 12 '18 at 20:35
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    $\begingroup$ @GNUSupporter8964民主女神地下教會 This isolated example shows nothing about CRUDE, since the delete votes and the associated comment came from the review queue, and the answer was never mentioned in CRUDE. Besides, I'm not sure tag scores are necessarily an indicator of expertise : for example I have a low score in "integration" because I don't really like to compute integrals, but I still know the basics and I think I'm competent to judge the quality of reasonably simple answers on the topic. $\endgroup$ – Arnaud D. Oct 15 '18 at 12:11
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    $\begingroup$ @ArnaudD. I see your points, but let me clarify my stance. 1. To be more precise, I would say that this post shows the influence of CRUDE participation on other posts (not listed on CRUDE). In a review queue, it's possible that one votes to close/delete within a few seconds. Given the amount of posts that they review every day (in/outside CRUDE), this example reminds us the adverse effect of their rare mistakes dispite their high reputation. 2. That's why I've added "contributing posts" inside the brackets. $\endgroup$ – GNUSupporter 8964民主女神 地下教會 Oct 15 '18 at 12:47
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    $\begingroup$ If you read the posts instead of the scores, you'll find out the truth: a) there's no probability theory in his/her "probability theory" answers. These are mistagged (elementary) probability questions. b) His/her stochastic calculus tag score comes from a reference request question. By the way, he/she has removed his/her comment. $\endgroup$ – GNUSupporter 8964民主女神 地下教會 Oct 15 '18 at 12:52
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Undeleted


I nominate Group algebra&algebra for undeletion so as to give the community enough time to judge this value of its answer, which is deleted due to the question asker's self-deletion.

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Reopened

(This is to break this request post into two)

I would like, if it is possible, remove the labels close-hold for some of next of my recent post Convergence of $\prod_{n=2}^\infty\left(1-\frac{1}{n^2}\right)^{i^n}$, where $i$ is the imaginary unit

I think that the answers are very interesting and very good, and I think that the questions are in the standard of questions of MSE. Any case many thanks.

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Please reopen The characteristic polynomial of $A$ is $x^n$ if and only if $\text{Tr}(A^i)=0$ for all $1\le i \le n$. due to the reasons listed in OP's comment. The first duplicate matches half of the question. The hypothesis of the second duplicate is different from the first one.

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Reopened

Please consider reopening Is there an injective homomorphism from $S_4$ to $GL(2,C)$ because the question asker has shown efforts in solving the problem, and it has a score of 4 with an accepted answer of score 3 from a 25k user.

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    $\begingroup$ Answers should not be used to judge whether a question should be reopened. But in this case, the asker did include sufficient context, so that's irrelevant. $\endgroup$ – user21820 Mar 25 at 9:44
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    $\begingroup$ "Answers should not be used to judge whether a question should be reopened." That's your opinion, @user – it is not a rule, or even a consensus. $\endgroup$ – Gerry Myerson Mar 25 at 11:51
  • $\begingroup$ @GerryMyerson: It is your comment that is an opinion; it's not even a consensus. Both this and this clearly demonstrate a consensus that "bad questions beget bad questions" and "closed questions can and should be deleted even if the have good but standard answers; only truly great answers should rather not be deleted". $\endgroup$ – user21820 Mar 25 at 12:37
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    $\begingroup$ @user21820 Thanks for your comment. I'll be aware of that next time. $\endgroup$ – GNUSupporter 8964民主女神 地下教會 Mar 25 at 16:39
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    $\begingroup$ @user, your quote refers to deletions, not closure/reopening; what's more, the part that says "only truly great answers should rather not be deleted" plainly contradicts your assertions that "answers should not be used to judge...." $\endgroup$ – Gerry Myerson Mar 25 at 21:51
  • $\begingroup$ @GerryMyerson: Firstly, if a bad question ought to be deleted, then obviously it should not be reopened. Secondly, it would be real silly to assume that everything I say is to be taken completely rigidly with no room for exceptions; from my very first comment I meant that as a rule of thumb answers should not be used to judge... $\endgroup$ – user21820 Mar 26 at 5:43
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    $\begingroup$ @user, I'm not sure how I am to tell which things you write are to be taken completely rigidly, and which allow room for exceptions. Maybe we could work out some signal, so in the future I'll be able to tell. $\endgroup$ – Gerry Myerson Mar 26 at 8:51
  • $\begingroup$ @GerryMyerson: Usually, I try to be precise, using words like "typically" or "almost always" but, you know, that that is very tiring to do in every single statement. How about you just assume that there may be rare exceptions unmentioned unless I use the word "absolutely"? I don't think anyone is 100% precise all the time anyway, so that works for interpreting others' comments too. $\endgroup$ – user21820 Mar 26 at 8:59
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Reopened

Please undelete Generalization of the fundamental theorem of duality since the question asker has deleted his/her own question shortly after receiving an answer. This is an abuse of the system.

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Undeleted and reopened

Please reopen Proving the greatest lower bound. because OP has self-deleted his/her own question after I've answered this question. This inhibits the community from viewing the question.

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Reopened

Please consider reopening the following question:

Maclaurin Series Expansion of $\ln(1+\sin x)$

The details which were included afterwards contradict the reason of closure. Moreover they indicate that the OP has as fundamental erroneous understanding of the concept of a MacLaurin Series - and how to derive them -rather than the unwilligness of showing his own efforts. In my opinion the question should be reopened.

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Reopened

Please reopen Am I have right answer about dual problem? since OP has responded to the comment and used MathJax to type out the math. In the revised version, OP has attempted to construct the dual program of the primal program, so it's OK for reopening.

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protected by Community Oct 1 '18 at 14:49

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