Honestly, the logic and proofs of CS isn't a big deal on the proof side. However the big O issues and sorting are a big deal.

If you get into languages, the language part of the proofs are important, but only insomuch as recognizing/identifying if something can be parsed with an X or Y or Z.

Just claim to be an intuitionist. Depending on your profs sense of humour, it's a valid answer.

Er... could you explain this?

I don't get it, I'm afraid =\

It's a reference to intuitionism, a constructivist approach to math and logic. Because the law of the excluded middle is disallowed in intuitionist proofs, you can't show what the parent comment was annoyed about.