Meaning of Clo(A), Int(A), Rint(A) I've just stumbled upon this notation in a text about optimalisation with no explanation as to what they mean (suggesting they are widely used and well known?). $A$ is a set (a convex set in this case) and the notation I am not sure of is: $$clo(A), int(A), rint(A)$$ I only need to know the names, as attempting to google these yielded no results. Thanks! edit: I just found < so that's probably one of them!

No, they are not widely used, so that is a BAD text for not defining them. My guess: Clo = closure, Int = interior, Rint = relative interior. (Also it is a bad text if it uses the word _optimalisation_ instead of _optimisation_.)