Problem 6. Prove or disprove the following statements:
1. Let A, B and C be sets. Then A β© (B β‘ C) = (A β© B) β‘ (A β© C).
2. If A and B are sets, then P(A) β© P(B) = P(A β© B).
3. If A and B are sets, then P(A) β‘ P(B) = P(A β‘ B).
4. If A, B and C are sets, then A β (B β‘ C) = (A β B) β‘ (A β C).
5. Suppose A, B and C are sets. If A = B β C, then B = A β‘ C.
6. Let A, B, C, D be sets, then (A Γ B) β‘ (C Γ D) = (A β‘ C) Γ (B β‘ D).
7. If m, n β β€, then {x β β€ : mn | x} β {x β β€ : m | x} β© {x β β€ : n | x}.
8. If m, n β β€, then {x β β€ : mn | x} = {x β β€ : m | x} β© {x β β€ : n | x}.