# Requests for Reopen & Undeletion Votes, etc. (volume 10/2012 - 12/2014) [duplicate]

The purpose of this thread is to help focus the attention of the community on posts that may require exceptional handling. This includes requests for reopen and undeletion votes. A request should be posted as an answer below.

Please do not use this thread to engage in debates on contentious matters (e.g. reasons for closure). That should be done in a separate linked thread. The goal is to keep this meta thread free of tension, so that everyone feels comfortable posting here. Please be polite, and respect the many different viewpoints in our diverse community.

To inform readers of the current (and past) states of the targeted post, please append tags such [REOPENED,RECLOSED] or [UNDELETED] at the start of the answer.

Beware that "short" requests such as "request reopening of <link>" may be automatically converted to comments by the SE software, so you may need to write more (e.g. why you think that the question should be reopened or undeleted).

• For reopen requests that are run-of-the-mill (e.g. aren't meant to debate reasons for closure), do you think it would make sense to have a generic reopen-request thread, so that we don't end up with hundreds or thousands of questions on such. Then each request would simply be an answer in the reopen thread, and it being bumped would get the same exposure as a new question. Thoughts? Unless I hear any objections I will create such a thread. – Bill Dubuque Oct 24 '12 at 17:11
• @Bill: Yes. This crossed my mind after posting this. I agree that it would be a good idea. – Asaf Karagila Oct 24 '12 at 17:37
• I didn't expect that you would edit this specific question into the general question (I was writing another). But since it is done, we may as well go with it. – Bill Dubuque Oct 24 '12 at 18:28
• @Bill: I saw no reason to wait with that idea. There was no actual discussion in this thread anyway. – Asaf Karagila Oct 24 '12 at 18:34
• @Gerry: The solution would be to add a few words, I suppose. For example why it should be reopened. – Asaf Karagila Nov 9 '12 at 12:16
• @Asaf, I opted for cursing the darkness rather than lighting a candle. Anyway, the question has been reopened. – Gerry Myerson Nov 9 '12 at 21:54
• @Gerry: Darkness is just the light's way of proving the empty set exists. – Asaf Karagila Nov 9 '12 at 21:55
• @Willie: I think that we should delete old reopening requests and perhaps have one post/additional thread for indexing them. I should also think that any request older than $n$ days for some reasonable $n$ should be deleted. If something has not been reopened and the initial votes expired... well, it makes sense to conclude that there aren't that many people interested in reopening. – Asaf Karagila Nov 30 '12 at 9:49
• @Willie It's probably useful to have some nontrivial history remain so that folks $\rm < 10K$ can gain some idea about what types of questions do get reopened, and what types don't. By quickly scanning the requests it might help to convey some idea of the community consensus on marginal topics. To keep the unopened requests at the top of the active sort, they could easily be bumped if there is still interest. – Bill Dubuque Dec 1 '12 at 1:44
• @Belgi: This is why I prefer to browse Meta with answers sorted by activity. – user856 Jan 5 '13 at 21:38
• @Belgi Sorting by activity solves the problem. I just bumped the only active discussion to the top with an edit. There are two requests dated by November 2012, which I guess are no longer ongoing conversations (but anyone so inclined can bump them; it's a CW). – user53153 Jan 5 '13 at 22:07
• Thanks for the workaround, I still think theres no reasons for this to log all reopen request that were/will be made – Belgi Jan 5 '13 at 22:10
• Per the (short) discussion in this deleted meta post, I have edited this thread to support requests for votes to undelete as well as votes to reopen. – Alexander Gruber Jul 13 '14 at 14:59
• The question got protected again; I'd assume, but cannot check, since it fulfills criteria for autoprotection The simplest way out would be to restart a question of this form. IMO this would be desirable regardless the protection issue. – quid Oct 17 '14 at 13:58
• @quid: Yes, yes, I see that protection triggering every time I remove it. But I gave it some more thought, and for now it seems harmless after all. – Asaf Karagila Oct 17 '14 at 14:06

[REOPENED. I cast the binding fourth vote on behalf of myself and Bill Dubuque]

This question: Prove $f(S \cap T) \subseteq f(S) \cap f(T)$ was voted to be closed as a duplicate of Is this a valid proof of $f(S \cap T) \subseteq f(S) \cap f(T)$?

However, the question asked actually was different. The latter asks for the readers to check whether the OP gave a valid proof (he didn't, and counterexamples were given as answers). The former asks for a proof. The closest answer we have on the latter to this question is this sketch of a proof. So I don't really think the two are exact duplicates of each other.

(The other proposed duplicate target is a mistake, as noted in the comments.)

• I agree, since your vote and mine bring the count to 5, you should feel welcome to reopen it. – Bill Dubuque Nov 6 '12 at 14:33

[REOPENED] I would like to see the question on "mathematics in the movies" reopened. It asks about feature films depicting math, and/or mathematicians. I think it is at least as relevant to math, and this site, as are many other "soft questions" that still stand as open. After all, we DO have tags "math history", "education", "big-list", etc.. If questions relevant to those tags are thereby subject to closure, then the tags should be removed from this site; else, they are appropriate topics on which to post.

If reopened, I think it might very well be appropriate to "wikify" the post (community wiki), but this question has merit.

ADDED, to answer Marvis's comment below: This post is not a "strict subset" of the post to which Marvis provides a link. They are sufficiently different posts to warrant separate consideration. (See for example, Rahul's reply to Marvis).

• I adjusted the link to direct to the question rather than to your answer, this is more fitting to the thread, and makes it easier to reopen/comment/etc. on the actual question. – Asaf Karagila Nov 22 '12 at 16:50
• Thank you, @Asaf (When trying to access the question, I clicked on my answer from my user page, scrolled up, copied and pasted the link - I intended to link directly to the Question!) – amWhy Nov 22 '12 at 16:52
• I would like the part about "what kind of stories would you like to see in the future" removed as it is discussiony and off-topic. I said that in my comment on the question, but the asker chose to ignore it and freak out instead. – user856 Nov 22 '12 at 17:50
• I believe that this question is a strict subset of math.stackexchange.com/questions/18843/… – user17762 Nov 22 '12 at 20:28
• @Marvis: It seems to me the questions are split along fiction/nonfiction lines. – user856 Nov 22 '12 at 22:42
• @Will Yes, rep is nice. But I already made my answer CW. My request to re-open was more about opening the question, not about gaining rep. I just thought there was a conflict of interest, in having drawn attention to a question I happened to answer. – amWhy Nov 23 '12 at 0:22
• points to comment that has been ignored yet again – user856 Nov 23 '12 at 20:10

[MIGRATED] I would like to see https://math.stackexchange.com/questions/256079 reopened.

• The stated reason for the closure ("not constructive") does not apply. There were answers, and they were supported by facts. The question did not solicit debate or arguments. There was a meta-debate, but it was about the appropriateness of the question, not its content; considering such a debate as a reason for closure would be circular, as one could then get questions closed simply by starting a debate on whether they should be closed. Nor is there any reason to expect that the question will solicit debate or arguments in the future. The question does fit our Q&A format; a question was posed and answers were given; that the answers were of the form "the question can't be answered because there's not enough information" is quite a common occurrence and not a reason for closure.
• The stated reason for the closure bears no relationship to the reasons for closure given in the comments. The reasons given in the comment are not valid reasons for closure. Personal opinions on whether the OP should or shouldn't try to assess the chances of his wife having a serious disease by asking a question on a math Q&A site shouldn't enter into the decision whether this question is suitable for this site. It's the OP's decision and not ours whether he wants to ask this question here.
• There were two answers at the time of closure, which had several upvotes and contained information potentially valuable to the OP. Even those who commented on problematic aspects of asking such a question on such a site can hopefully agree that it's good if the OP knows that there's not enough information in his question to answer the question.
• I don't know the current status of the close vote cancelling policy proposal; it may or may not be relevant that I cast a no-close vote in a comment, no-one cancelled it and it received three upvotes.
• If you have a homework problem, you post it on m.se; if you have a life-or-death problem, you don't spend your time m.se, you hire a professional. That's the advice this person needs, and it can be given as a comment; there's no need for an answer. I don't want to think about the consequences for m.se should someone, in good faith, give a misleading answer which causes some real harm. – Gerry Myerson Dec 11 '12 at 12:33
• @Gerry: My main point is that this is for the OP to decide, not for us. It seems that you and others disagree (though I don't think any argument against that principle has been offered yet), so I'll argue on the merits even though I think we shouldn't: Many questions are life or death questions. If someone posts a question on how to optimize a process and save the government a lot of money, that money can be invested in better hospitals or safer roads instead; yet no-one would claim we shouldn't be giving mathematical advice on that optimization. – joriki Dec 11 '12 at 12:51
• This question is more directly related to life and death, about as directly as the present question. It has $150$ upvotes, no close votes and $17$ answers, one with $48$ upvotes. Should it be closed? If not, where is the difference? – joriki Dec 11 '12 at 12:52
• joriki, the difference is that the programmer asking about ambulance schedules has some ability, however untrained, to translate correct mathematical observations to working code, and to discard that code if it fails simulation tests. This poor guy, whom I now believe to be legitimate, has no evident ability to correctly formulate his problem, nor to translate an answer into a better choice for his wife. His demands for a short and simple "answer" demonstrate that much. – Will Jagy Dec 11 '12 at 21:45
• I left a comment for Michael Hardy. He can cast the final vote to re-open and post an answer, if he sees some purpose to that. His Ph.D. is in statistics, although that does not guarantee he has tables of useful percentages in epidemiology. – Will Jagy Dec 11 '12 at 22:08
• For what it's worth, if "someone posts a question on how to optimize a process and save the government a lot of money," I would tell her to go away to hire a consultant. – Gerry Myerson Dec 11 '12 at 23:54
• The question was migrated to stats.stackexchange.com/questions/45807/… For the moment, there is also my question stats.stackexchange.com/questions/45804/… with an excellent answer by an epidemiology guy, but the two questions will probably be folded together. – Will Jagy Dec 13 '12 at 0:35
• As Will noted, the question has been migrated. Should we edit this answer to include a note to that effect? – Willie Wong Jan 4 '13 at 15:46
• @Gerry: Yes, you might tell her to go away to hire a consultant, but you wouldn't vote for the question to be closed (and certainly not as "not constructive"). Of course you don't have to do unpaid work in such a case if you don't want to, and perhaps no-one wants to and then the question remains unanswered; but this entire site is about doing unpaid work for people, and such a question would be perfectly legitimate here. – joriki Jan 6 '13 at 8:18
• @joriki, I don't mind doing unpaid work to help people learn mathematics. I do mind doing unpaid work to help people in private money-making enterprises. If they are going to make, or save, some money out of it, they should be willing to pay someone to help them. – Gerry Myerson Jan 6 '13 at 15:19

I really hope we can get past this anti-computer attitude. If you don't want to do computational mathematics, that's fine, but please don't obstruct the participants who do. Just ignore the tags if you don't like the questions.

"We welcome questions about: ... Software that mathematicians use" - FAQ.

It's a reasonable question and the current answer lists only one way to create arrays in GAP. There is still more to be learned.

For the same reason, I voted these to be reopened:

https://math.stackexchange.com/questions/209266/how-do-i-break-magma

and

• Please be sure to follow your thread and update if the post has been reopened. – Asaf Karagila Apr 22 '13 at 13:47

[REOPENED] Find $\det X$ if $8GX=XX^T$ was closed as not a real question. I have edited it in light of comments by OP. I think it's a real question now (albeit an easy one, that I have answered in the comments).

[REOPENED] What explains this bizarre behavior?

I would like to see this question reopened. I believe it is a valid dynamical system question.

• I voted to reopen. The OP noticed a very interesting effect that has puzzled a lot of people over the years. – Cheerful Parsnip May 4 '13 at 15:53
• @Grumpy: More accurately, we noticed an interesting effect, and we are assuming the OP noticed what we noticed. (And admittedly, I did not notice, because my eyes glazed over at the wall of digits and I didn't see the signs, although I did track the pattern of the decimal point) – user14972 May 5 '13 at 1:01

[REOPENED] (Thanks!)

I would like to see this question reopened.

In fact, I do not understand why it was closed to begin with: The OP posted the question, and illustrated with examples what they meant. The question does not appear trivial, and its formulation takes some preliminaries, so it cannot just be stated in two lines.

In case the question is not clear, let me rephrase it as I did in the comments (but really, looking at the examples the OP provides may be better than chasing through the formalism here):

Let $f,g$ be any linear functions from $\mathbb R$ to itself. If $h$ is a function obtained by composing $f,g$, in any order, say $h=j_1\circ j_2\circ\dots\circ j_n$, where each $j_i$ is $f$ or $g$; and $s=s_h$ is the fixed point of $h$, then we can associate a cycle to $h,s_h$ by considering the finite sequence $$a_0=s_h,\quad a_1=j_n(s_h),\quad a_2=j_{n−1}\circ j_n(s_h),\dots,\quad a_n=j_1\circ \dots\circ j_n(s_h)=s_h.$$ (Note that the $a_i=a_i(h)$ depend on $h$.) Define $\mathrm{Sum}_g(h)$ as the sum of the $a_i$ with $i<n$ such that $j_{n−i}=g$.

Now, let $S$ be obtained by composing $f,g$ in any order, and let $T$ be the result of composing in the reverse order, so if $S=j_1\circ\dots\circ j_n$, then $T=j_n\circ\dots \circ j_1$. The question is: Is it true that we always have $\mathrm{Sum}_g(S)=\mathrm{Sum}_g(T)$? If so, how can we prove it?

[REOPENED] I have no doubt about what this question is asking and have actually posted an answer in the form of a pair of comments. I’d prefer to give it a ‘real’ answer, however. I note that the question already has three votes to reopen.

Prove $f=x^p-a$ either irreducible or has a root. (arbitrary characteristic) (without using the field norm) has been closed as a duplicate. But the answer at the earlier question uses field norms, and OP wants an answer not using field norms.

[Now Deleted]

OP has put some work into improving https://math.stackexchange.com/questions/436733/trigonometry-right-angled-triangles#comment936496_436733, so I nominate it for re-opening.

EDIT: now deleted. Can a deleted question even be re-opened?

• I think posting questions as a scanned file or photograph should be discouraged. It would be difficult to give the question not in this way, but an attempted solution should be typed out. Apart from anything else, you are expecting anyone who answers this to put in more effort than the OP has done! (Thus, I am not voting to re-open, although I have no qualms about others doing so.) – user1729 Jul 7 '13 at 14:09
• I agree that what OP has done is not optimal. I think OP deserves some credit for engaging with criticism. – Gerry Myerson Jul 7 '13 at 23:07
• Question currently has 4 votes to reopen --- and 2 votes to delete. – Gerry Myerson Jul 11 '13 at 9:32

[Now deleted]

I would like to see this big-list question re-opened. It is on the "Real-world applications of the Fibonacci Series". As I said in the comments, I do not think that this question should be closed. There is a [big-list] tag for a reason. The tag's wiki says "Please do not ask too many of these" not "Do not ever ask these".

Also, I believe that wondering about the applications of different aspects of mathematics is a worthwhile thing to do! If you ever have to write a fellowship application, then it is doubly worthwhile! However, the comments seem to be saying "How dare you ask about applications of mathematics! We do not care about such trifles here!"

I would be grateful if those who want to keep the question closed could comment here on why they have this opinion. You have heard my view, and I am interested in hearing yours.

• @Downvoter: When I wrote "I would be grateful if those who want to keep the question closed could comment here on why they have this opinion", I was talking to you... – user1729 Jul 17 '13 at 12:15
• Sorry I just saw this. I think the question should remain closed until the OP has suitably narrowed the question down (or split in to distinct posts) to something which can be answered in a few paragraphs. As it stands, there are two 'big list' questions only tangentially related to each other, and another question which could receive some great attention as a history of maths questions if posted separately. I've added a comment to the same affect on the question. – Dan Rust Jul 24 '13 at 12:59

[Re-closed as duplicate about Cartesian to Polar change of variables. See comment below.]

I propose that we should reopen this question question, and posted my reason in the comments.

It was closed as an exact duplicate of a thread asking how to evaluate a Gaussian integral. But actually, the question was why, when one converts from Cartesian to polar coordinates, $dx\,dy$ gets replaced by $r\,dr\,d\theta$. That's not what the other question was about. There are other ways to evaluate the Gaussian integral than by polar coordinates, and those other ways would be appropriate answers to that older question, but not to this one. In some ways, the presence of a Gaussian integral in this question is incidental. It was really only the particular occasion for the question about polar coordinates.

[REOPENED]

This question (A) was closed as a duplicate of this one (B), but question B has no answers and question A already had one on closing. Question A also had much more detail in the question itself.

I pointed out the first fact in the comments while close votes were being cast but it was closed anyway.

I think question A should be re-opened. It might be worth considering whether B should be closed as a duplicate of A as well.

• I agree with the general idea, but is it even true that (B) is a duplicate of (A)? In that, they have the same underlying questions but asking for different help with them? (Although I haven't read them in detail - they are long!) – user1729 Aug 29 '13 at 17:30
• @user1729 same here, I must admit. I think A should be reopened at the very least. – Antonio Vargas Aug 29 '13 at 18:04
• Yes, I agree that (A) should be reopened. – user1729 Aug 29 '13 at 18:36
• You can reopen A, and close B as I am concerned (I asked them), the problem came because there was migration involved from physics SE. – dingo_d Aug 29 '13 at 21:59

The person who asked this question has now added the missing photograph, and it’s now clear what is wanted: an example of a regular, non-normal space other than the Sorgenfrey plane. I expect that the OP would like a simpler example. (Note: it’s clear from the photo that the notes use the backwards convention in which $T_3$ and $T_4$ do not include $T_1$.)

• You seem to be putting much of yourself into this: according to their own comments, the OP does not ask for an example of a space with such-and-such properties, they want to "know whether (their) examples are correct or incorrect". (Unrelated: are you actually able to read the photograph?) – Did Sep 29 '13 at 7:49
• @Did: That comment hadn’t yet been made when I posted this request. I actually can read the photo with a bit of work just as Firefox displays it on the question page, but I don’t bother: it’s easy to read when I open the image in a new tab and view it at actual size instead of reduced to fit the screen. – Brian M. Scott Sep 29 '13 at 19:08
• The chronology is irrelevant to my point. What do you think of "it’s now clear what is wanted" in your post here? – Did Sep 29 '13 at 19:16
• @Did: Isn’t it obvious? What he said at the time was reasonably clear; it also turns out not to have been what he wanted to say. shrug It happens. It’s also beside the main point, which is that he added the missing photo. – Brian M. Scott Sep 29 '13 at 19:32
• Sorry but as far as we know the OP always said exactly what they wanted to say. I have no idea why you pretend otherwise (furthermore, declaring that it is "obvious" that they did). But hey, this universe is full of mysteries, aint'it? – Did Oct 1 '13 at 12:54
• @Did: If you really believe your first sentence, you must live in an ivory tower and have very little contact with real people. – Brian M. Scott Oct 1 '13 at 19:04
• Thanks for the compliment. Of course, the first sentence refers to this OP and to this question, not to every question and every user on the site (to even imagine that I would argue that in every question etc. ..., wow!). And "always" refers to the fact that at no stage of the question, the OP said what you based your request for reopening upon. – Did Oct 1 '13 at 19:08

[REOPENED]

The question Is there a continuous bijection between an interval and a square: $[0,1] \mapsto [0,1] \times [0,1]$? was closed as a duplicate of an older question A bijective function between a square and its side

In my opinion, the newer question is better formulated (for example, the title corresponds to the body of the question) and it has more answers. So I suggest to reopen this question and close the older one as a duplicate instead.

(I have suggested this in the comments and in chat before the question was closed. This might be the reason that the older question has already received two closed votes. However, now that the newer one is already closed, it cannot be chosen as a target for closure of the older question as it would cause circular duplicate links.)

EDIT: Since the newer question is already reopened, the older one can now be closed as a duplicate.

Edit 2 (LF): Older question is closed.

• I agree with your proposal. However, I wonder if it would be better to make this into a proper meta question as opposed to leaving it here? – user1729 Oct 1 '13 at 11:38
• @user1729 It seems that combination meta + mentioning this in chat worked in this particular instance. – Martin Sleziak Oct 1 '13 at 12:09
• Sorry - I should have mentioned why I thought that. It was so that we could have a question which discussed this case and which could be used as precedent for future cases. Currently, the precedent is hidden away here and so isn't going to get the exposure needed for it to be a proper precedent. – user1729 Oct 1 '13 at 12:19
• @user1729 There already is a post about this: Topics declared as duplicates in which order?. (Although there are no answers there and that post seems to me to be about a particular instance, not about a general principle.) Feel free to make a post on meta about this problem, if you think it is needed. (I think it might be better to discuss the general principle on meta rather than some particular case of this problem.) – Martin Sleziak Oct 1 '13 at 12:25
• It's not a huge discussion, but nonetheless the ultimate precedent is probably this mother-meta post: meta.stackexchange.com/q/48838/146482 – Tobias Kienzler Oct 2 '13 at 6:34
• Here's a related question on meta.math, though I'm not happy with the accepted answer... – Tobias Kienzler Oct 2 '13 at 6:49

[REOPENED]

A formula for the power sums: $1^n+2^n+\dotsc +k^n=\,$? , from a user investigating that sum, presents a method that the OP tried to get the sum in closed form, observes that it doesn't work well, and then asks “are there other ways?”

The purportedly "duplicate" question Finite Sum of Power? also asks for the closed form, but not for a derivation, or for techniques to approach the problem, and the answer there doesn't give any.

(I voted to close the question, and on reflection, I regret my vote. I have voted to reopen it. I will try to be more careful in the future.)

• I've also done a comment from a bit of getting "sour" - but possibly "too much": occuring as a halo from some surrounding/related questions last time. I even overlooked (like you) that there was own work on the question - however I couldn't believe that someone would not look at wikipedia for something standard like this.(I think we should not attempt to rewrite wikipedia in MSE). So -maybe- my sour comment might have contributed to the "close question" call... Sorry for that. – Gottfried Helms Oct 23 '13 at 9:02

[NEVER MIND]

There's a revised Question about "proportion" of prime numbers to non-prime numbers that the OP wishes to have reopened.

I'm somewhat lukewarm about this, but after reviewing our stock of Q's on the Prime Number Theorem, it seems some technical but valid to ask what the PNT tells us about the ratio of primes to non-primes (below a threshold natural number $n$).

If I felt the (new) user were more mathematically adept, I guess I'd be more enthusiastic about reopening. However I suspect I'm projecting a meaning onto the request that is more sophisticated than what the OP is thinking.

• I disagree. The question shouldn't have been edited in the first place (it invalidates existing answers), and I have reverted. Perhaps it should be a new question. – Lord_Farin Oct 31 '13 at 13:48
• It seems the OP is happy with a Commenter's link to another Question, similar to the revised one that has been reverted. – hardmath Oct 31 '13 at 13:55

[REOPENED]

I would like this question reopened. Closing it because the OP didn't state anything beyond the bare question is a little harsh, and the question is interesting.

EDIT: Paul Siegel's answer has been accepted with 3 upvotes. That seems to indicate that reopening is appropriate.

• Why not wait that the OP "add(s) in what (they) have tried and where (they) came across", as was suggested to the OP in a detailed comment? – Did Nov 3 '13 at 21:40
• @Did: because closing it seems like a heavy-handed way to get the OP to respond. The detailed comment that was left was more than sufficient. – Cheerful Parsnip Nov 3 '13 at 22:22
• The problem is indeed interesting, and currently has a solution that could use checking (I fixed some of the problems, I think, but I don't know if I did so correctly). I don't know, however, about the bad precedent that could set.... – dfeuer Nov 5 '13 at 2:02
• @dfeuer: There are plenty of questions where the OP only states the problem which have not been closed. Closing this questions strikes me as absurdly harsh. – Cheerful Parsnip Nov 5 '13 at 2:27
• Of course the best turn of events would be if the OP edits. – Cheerful Parsnip Nov 5 '13 at 2:28
• @GrumpyParsnip Two weeks later... and in view of the subsequent (or lack of) events, do you still hold the same view? – Did Nov 17 '13 at 14:47
• @Did: maybe a good course of action would be to reopen - and wiki-fy - the question. Then the OP doesn't get any reputation (and the thought that they did anything right...), but the community still gets the benefit of having answers to the question. Granted, there are already answers... – The Chaz 2.0 Nov 17 '13 at 15:10
• @Did: I still think it deserves to be reopened, even if it has been abandoned by the OP. It's the question itself that is interesting, not the person behind it. – Cheerful Parsnip Nov 17 '13 at 19:52
• It's really not clear to me how one goes about drawing enough attention to reopen. – dfeuer Nov 26 '13 at 16:50
• @dfeuer: I edited the answer to bump it to the forefront. – Cheerful Parsnip Nov 26 '13 at 17:23
• @dfeuer: thanks for fixing my comment. – Cheerful Parsnip Nov 26 '13 at 19:17

[REOPENED]

This question is typical basic linear algebra homework, directly pasted from the textbook. So it sure looks bad at first.

But read until the end... the OP actually proposed answers for every question and is simply asking for confirmation. So s/he probably did not get that from an answer key.

This certainly includes the OP's attempts to solve the problem, and I don't understand why it was closed. At least not for the specific reason which is mentioned. What is unclear here for sure is the message sent to the OP...

[REOPENED] Thanks.

This question has been put on hold as off-topic. I would like to see this reopened because:

1 - Unless I missed something, this is not exactly an easy question. If it is, anyway, I would really like to see easier solutions. This was not a routine reasoning for me, so if I made mistakes, I would really like interested people to point them out.

2 - For sure, it is a natural one for which the context had been provided by the OP: s/he mentioned Carleman's and Hardy's inequality, and this is the $p=-1$ case of the latter which is known to hold for $p>1$ when you read the wikipedia entry, for instance.

3 - Although I expect an OP to share some thoughts/efforts, on a trivial/standard question, I don't care if the OP does not add "I tried this (whatever) and it did not work, can you help me please?" on a harder question.

4 - This is the question I've been the most interested in for quite some time. I did not even know about Carleman's and Hardy's inequality: so I've learned something and I have had a lot of fun looking for the answers. Exactly what I am here for.

5 - I would enjoy seeing other answers with different approaches.

[REOPENED]

The author of this question added the requested details before the last "no context" vote was cast, so the question should be reopened.

reopened

This question was closed. It seems to have been edited in the meantime, and seems reasonable to me at this point.

I gave a partial answer in a comment, but it would be more convenient for everyone if it could be reopened and answered properly (with hints, further explanation, whatever people find appropriate).

[REOPENED]

In my relatively expert opinion this question is perfectly clear. Yet it was put on hold as unclear what you are asking. The OP also has put a rather non-trivial amount of effort into understanding the question given that they say to have implemented the usual Viterbi decoding algorithm. Admittedly the OP has built a bit of a history in asking coding theoretical questions that actually are unclear and/or show very little effort. This question is not one of those. I will answer it in a comment (it has a very quick answer), and let anyone else take a first bite at answering. But keeping this on hold sends IMHO a wrong signal.

This question about radian measures was recently marked as a duplicate of this question about $\pi$ being the same for all circles. The former question asks 2 concrete questions in its body, and I feel that at most one of them is covered by the latter question. I think it would be better if the question about $\pi$ were mentioned in a comment, rather than designated a duplicate.

Note: I don't have 3000 rep, so when counting reopen votes, don't count mine.

[REOPENED; thank you]

Ambiguity in the Natural Numbers asks what seems to me to be a very clear and specific question about whether two different axiomatizations of the natural numbers can contradict one another. This has been a serious research subject in the past, and it admits a positive answer, which Henning Makholm and I independently wrote.

It was closed as "unclear", but I disagree.

My questions are numbered in bold. What's purported unclear?

Sequel — Fev-6-2014 — I edited. The question has more original text now.

• Pretty much everything is unclear. What are all those boxes? What are all those circles? what are all those squiggly things beneath the circles? What's your, and what comes from the textbook? What is the textbook trying to do, and what are you trying to do, and what exactly are you asking us to do? – Gerry Myerson Feb 6 '14 at 8:36
• Good, it's better now. – Gerry Myerson Feb 7 '14 at 10:10

My question is long but I put my questions in the gray shaded boxes. Questions are numbered too and spaced. Ergo it should not be 'unclear what you're asking.' None of the closers commented?

• Did you see where it said, "Beware that "short" requests such as "request reopening of <link>" may be automatically converted to comments by the SE software, so you will need to say more, such as why you think that the question should be reopened. "Please do not use this thread to engage in debates on contentious matters (e.g. reasons for closure)." – Gerry Myerson Mar 1 '14 at 23:21
• @GerryMyerson: thanks. did the website convert this to a comment? i didn't know. i wrote about the numbering too. is it enough now? i don't want to essay too much. – Nai Mar 2 '14 at 6:10

My question is long but I put my questions in the gray shaded boxes. Questions are numbered too and spaced. Ergo it should not be 'unclear what you're asking.' None of the closers commented?

• Did you see where it said, "Beware that "short" requests such as "request reopening of <link>" may be automatically converted to comments by the SE software, so you will need to say more, such as why you think that the question should be reopened. "Please do not use this thread to engage in debates on contentious matters (e.g. reasons for closure)." – Gerry Myerson Mar 1 '14 at 23:20
• The question has since been automatically deleted by the Community user. – user61527 Mar 16 '14 at 19:01
• @T.Bongers And, worse, 10K users cannot vote to undelete since a Community bot deletion counts as moderation deletions. Bots should not be considered smarter than users regarding such. – Bill Dubuque Mar 17 '14 at 3:58
• @BillDubuque: Dear Bill, A revised version of the question has since been posted (by the same OP), but in a Catch-22-like situation, has been closed essentially for being a duplicate of this (now deleted) question. I have voted to reopen the new question; maybe you would like to as well, since the old question seems irretrievable? Regards, – Matt E May 5 '14 at 11:21
• @MattE Thanks for the notice. I too voted to reopen the newer version. I find it very disturbing that some users are not only voting to close these questions, but also to delete them (e.g. this newer one). These questions show genuine concern about understanding the essence of proofs. Yet questions that don't, but merely have random content injected in order to meet the "show effort" constraint remain opened and rewarded by the same users. What a sad state of affairs. – Bill Dubuque May 5 '14 at 14:11

The 2012 question Prime counting inequality was put "on hold" two days ago, with the reason "unclear what you are asking".

I think the question is clear: what is the largest $c$ such that $\pi(x)>cx/\ln x$ for all integers $x$ [in the range where function $\pi$ makes sense]? It admits an answer: $c=\ln 2/2$. Not a very exciting answer, but not entirely trivial either. I see no reason at all for this question to be closed.

• Ah, but you are misquoting the question: it was asked for all integers $n$, not $x$. This led to a commenter asking whether $n$ was supposed to be $x$, a question which the author did not answer. So, technically, the question is unclear. But on the whole I don't see where closing it does any good. – Gerry Myerson Mar 3 '14 at 6:40

Please reopen https://math.stackexchange.com/questions/713610/having-elements-as-ideals . The question is in my opinion clear (I have edited it to make it maximally clear). The main problem of clarity seems to be other people assuming I am unclearly expressing an idea other than the idea I am expressing explicitly, because its such an odd idea/question. That is, they assume I am being unclear or figurative because they refuse to take my words at face value.

• Without rendering a judgement on the question itself, "The main problem of clarity seems to be other people assuming I am unclearly expressing an idea other than the idea I am expressing" seems to be the very definition of "unclear." – user61527 Mar 16 '14 at 18:59
• @T.Bongers Point well taken. I clarify in the next sentence what I mean though. People are assuming I am being figurative or mistaken, instead of just reading the words I am writing as literal. – Jacob Wakem Mar 16 '14 at 19:10