Let S be a set in Rn, is it true that every interior point in the closure of S is in the interior of S? Justify. ie. int(closure(S)) a subset of int(S) It seems to me that it would be true...if you could say that the interior of the closure of S is the interior of S unioned with the interior of the boundary of S, then it would have to be true because the interior of S's boundary is the empty set. Does that make sense?