Out of curiosity. If a moderator deletes a question, I know that it's impossible to undelete it by regular users. When a moderator undeletes a question, is it impossible for regular users to delete it? What about "OP binding vote"?

@AsafKaragila Ordinary user can then delete the post again. In the case at hand, the answer got an upvote after the undeletion, so the asker can't delete the thread themselves again (unless the upvote is retracted).

@DanielFischer Thanks.

Hello, I don't know where to write this. I found this room from a link on a meta threat. My concern is that someone recently deleted a post which I have answered. I can't see the post or my answer anywhere. Is there anyway to undelete that post. The post was about projective geometry and proving concurrence of three lines.

I forgot to say this: The post deleted right after my answer. I think the question was a homework problem and the OP was trying to cover the traces. From the meta threads I have read, in these cases we need to contact a moderator.

@iamvegan Probably mods will be able to help you more (and additionally I am not sure whether this behaves differently for users below 10k and above 10k) but do you see something if you click on "deleted recent answers". You should find something like that below your answer on the answer tab in your profile: math.stackexchange.com/users/current?tab=answers

This show also a screenshot where to find it - for question, but for answers it should be similar: What is the 'deleted recent questions' page in the user profile?

@MartinSleziak Thanks a lot. Yes now I saw the link of the deleted post now. math.stackexchange.com/questions/1970276/…

I can't flag this though.

Ok, now that link was found any 10k+ user can vote to undelete. (IIRC it would need 3 votes.)

10k+ users can see all deleted posts, but they can't search for them. (I.e., I only can see it now because you gave me a link.) I knew that users below 10k can see their own deleted posts if they have a link. (For deleted recent questions they can be found in the way you just did.) And, as I just learned from you, they can also see their deleted answer.

So I voted to undelete (2 more votes are needed). But I think that - since you posted this in the mods' office - the moderators will probably handle this before 2 more regular users will cast their undelete votes.

BTW Menelous' theorem is either a typo, or that theorem has two different common spellings. (The Wikipedia article you link to spells it es Menelaus' theorem.)

@iamvegan It's back. But you misspelled Menelaus.

@DanielFischer Great! Also thank you for noticing the misspelling :)