Was this question on the HNQ at some point? I can see no other justification for the large number of upvotes (on the question and answers), given that it is essentially a PSQ...
@CarlMummert Yar... I wouldn't take that question on a date, but it isn't nearly as uncouth as it was before. I've voted to reopen. The accepted answer, on the other hand, is of a style that find to be a poor fit for the stated purpose of creating a repository of questions and answers.
For this one, it happens I can write a pretty comprehensive answer. I try to empathize when questions are edited - compared to the editors who never respond when a question is closed...
I must be on the opposite of the world, as I just got into the office, poured my first cup o', and am now putting together the last bit of lecture for the morning
@user21820 Why did you just edit a question that ought to be deleted? If you disagree, and just edited to make the question look better, why didn't you say so here?
Most of the answers to "why" basically boil down to restating the definition, and the one or two good answers there would also adequately answer the "what" question.
@user21820 Why did you need to emphasize explicitly that "amWhy" voted to close the question, when the OP can see that already, plain as day? I don't understand your sometimes inconsistent actions on questions. That said, you are free to act as you see fit.
@amWhy I'm not being inconsistent here as far as I can tell. The asker (as per his/her last comment) said "amWhy did realize that it is a legit question and tried helping unlike rest who thought else", as if the closure was unjustified. I wanted to point out that I agreed with the closure and that you were one of the close-voters as well.
That's all.
Closing is a separate matter from not helping, and the asker was (in my opinion) clearly conflating the two.
That kind of question - "characterize the set of points of discontinuity of a function" - is exactly the kind of thing that would have been interesting in the very early 20th century, early descriptive set theory
@XanderHenderson I've met two dozen questions that fit that description in the last few hours, unfortunately. Can't vote or take action until a tad less than an hour from now.