Thread: Proofs

1.
Prove: For all sets A and B, if A is a subset of B, then not B is a subset of not A.

2.
Prove: For all sets A,B,and C, A - (B U C) = (A-B) and (A-C)

#1 is really only about logic. Recall that .
Thus “If x is in A then x is in B.” is equivalent to “If xi is not in B then x is not in A”.

#2