# Proof-verification and duplicates.

When someone posts a question, which asks for verification of their proof of something, the mathematical content of that question will often be a duplicate of another question.

Now, in order to help the asker, the question should not be closed as a duplicate, since it is highly unlikely that the actual question is a duplicate (this would require someone else to have asked for verification of a proof that was identical to the one given by the asker).

On the other hand, once the verification of the proof has been dealt with, it seems like it might be a good idea to mark the question as a duplicate (assuming the mathematical content really is a duplicate of course), since a later visitor searching for phrases related to the question might come across this one first, and it would likely help them to be redirected to a place where the question was about the mathematical content, rather than on the details of a specific attempt at a proof.

I would therefore propose that when people see a question where the verification of the proof has been dealt with, they vote to close as a duplicate.

(This proposal is inspired by the question Any two sets $Y$, $Z$ have the same cardinality $\iff$ there are injective functions $f: Y \rightarrow Z$ and $g: Z \rightarrow Y$. and the request for reopening of it).

As I may well be overlooking something important here, this thread is of course also an invitation to discuss the proposal.

• What about mentioning the other question in comments instead of closing. In this way: 1) You don't have to wait until the question is answered. 2) The other question remains among linked questions. (If the question is reopened, the link is removed from the post and thus the other question may be removed from linked question unless it is mentioned elsewhere.) – Martin Sleziak Sep 23 '13 at 13:47
• @MartinSleziak Closing as a duplicate puts the other question at a more prominent position when you look at the question about verification of the proof. In particular, if you are a new user, you might not consider looking at the comments (the comment thread can get long on proof-verification questions), and certainly not at the list of linked questions. But there is no way to miss the big "this is a duplicate" notice. But it does sound like a good idea to put a link in the comments as one of the first things. – Tobias Kildetoft Sep 23 '13 at 13:50
• It would also be useful if those closing in such a situation would explain why they are doing so (and also link to this thread). Otherwise, people will think it is encouraged to close such unanswered questions as duplicates, and other similar repercussions will occur. – user1729 Sep 23 '13 at 14:11
• I object strenuously both to closing a legitimate question that is not in fact a duplicate and to falsely labelling such a question as a duplicate. I have very little sympathy for anyone, new user of not, who does not read the comments, especially the comments that obviously contain links. – Brian M. Scott Sep 25 '13 at 3:38
• Not to mention, some proof verification questions are much higher quality than the primordial version of the asked question. I think simply tagging the proof or solution verification pretty well provides any demarcation which is needed. Besides all this, as a person searching for answers, it might actually be better to have a few duplicates in all honesty. – James S. Cook Oct 5 '13 at 4:22

Personally I think that it would be bad practice to close a question that is perfectly valid, it just doesn't feel right. (This is possibly in part because the question isn't really a duplicate, it is just about the same subject matter so I object to calling something a duplicate when it's not.) It might also annoy people who ask this type of question if they don't know why the question has been closed, as well as discourage others from asking proof-verification questions because they are often seen to be closed.

I can understand the reasoning behind wanting to make it easy for people to search for general answers to a specific problem as opposed to just how to finish off a particular proof, but any question closed this way would need to have a comment on anyway explaining why it was closed, so why not just leave a comment pointing to the more general version? If I was searching for something in particular and I found a question which wasn't what I wanted, I'm not sure that I'd follow a link to something it was a duplicate of, because I'd think that it was the same thing. The only way that I would do would be if I saw a comment explaining why it was marked as "duplicate". However, if I had seen the comment I wouldn't need the question to be marked as a duplicate!

• I couldn’t agree more. – Brian M. Scott Sep 25 '13 at 3:34

Please add tags like and to these questions. There are now 367 questions in those tags but the untagged number is much higher.

There are a lot of users in one of the two categories:

• prefer to read/answer these postings, which by definition contain "displayed effort"

• want to avoid questions that involve line-by-line analysis of other people's work

Question titles do not tell that a posting is of this type. With tags it can be seen from the front page, and the process can be automated with Favorite/Ignored settings.

Tagging would make it clearer that a *-verification question is not a duplicate of the generic question, and could assist the search for genuine duplicates if they exist within the tag.