Let A and B be closed sets in a topological space X. (0, 0, 0, 0), then An B = . (a) Prove that if IA,B (b) Prove that if IA, B (c) Prove that if IA, B 1 - A B, and B A. (1,0, 0, 0), then An B : . = (1, 1, 1, 1) or (0, 1, 1, 1), then Int(A) ^ Int(B) ,