Proof subset???? Given three sets A, B, and C, set X = (A-B) U (B-C) U (C-A) and Y = (A∩B∩C) complement C. Prove that X is subset of Y. Is Y necessarily a subset of X? If yes, prove it. If no, why??? ---When I draw the two venn diagrams X and Y, they are the same, but I don't know how to prove it... Can someone help me out here... Thanks in advance!