Hello All,
Topology is just getting under way for me, and I have a question.
Consider a set {n}. Is it open, closed, or neither? Specifically, say {8}, for example.
I say this set is closed, because it has upper and lower bounds at {8}. Also, as I understand it, the compliment {(-inf,8) u (8, inf)} is open. Thoughts?
All input is greatly appreciated.
SY