A recent question on the complexity of sorting a countable infinite set (Sorting of countabe set) was apparently deleted. I'm curious why.
(Certainly, the question was poorly written, with no motivation or evidence that the OP had put any effort into answering it on their own; so it should have been (and was) closed. However, I think that there was a very interesting question lurking there, and left some comments in that direction, suggesting that the OP rewrite their question. Without knowing anything else, right now I think that question should have remained undeleted, to give the OP a chance to do so.)
EDIT: The text of the relevant question, as well as I can remember it, was: "Can a countable set be sorted in countable time? I know a finite set can be sorted in finite time, but is that still true for countable sets?" This question appears to me somewhat subtle, depending what order-type the set being sorted is allowed to have, and exactly what "countable time" means.