@user21820 Well, the fact it has a mistake is beside the point, right? We don't delete answers simply for containing a mistake, we would just downvote and comment. I think it's guilty of being not-an-answer though, so the delete vote it has accumulated so far isn't totally unwarranted. I just didn't want people to walk in here and start thinking we subscribe to wholesale cleansing of things-not-perfect.
@rschwieb It is a serious disservice to the many students who come across that terrible answer if we do not delete it. It is made even worse by the silly upvotes (which now have been negated).
That said, I upvoted your comment, which is good to have while the answer has not yet been deleted.
@user21820 Well, I'm not saying it shouldn't be deleted. I'm just saying it would be easy for people coming here to misinterpret the message you left as "OMG X has a mistake, pile on and delete it."
It actually looks like a plausible answer (with an inaccuracy), just not an answer to this question.
@darijgrinberg What context? All I see is a question and some minimal case work. I see no indication of where the problem came from or what tools the asker expects to be able to use to answer it (theorems, etc). The asker hasn't even defined the notation $\omega(n)$ (one may infer it from context, but the notation is not defined).
@darijgrinberg Although it isn't as bad as instances of cheating, it seems a rather poor question with hardly any context. Why on earth is he "trying to prove the dimension of intersection of the subspaces is 0"?
@darijgrinberg That improves the question from "unclear" to "clear, but lacking context." I don't see this as a significant improvement (otherwise, I might have done it myself).