4. Let U = 81, 2, 3, . . . , 9 6. Suppose that U is an infinite universal set, and A and B

4. Let U = 81, 2, 3, . . . , 9<. give examples to illustrate the following facts:>

6. Suppose that U is an infinite universal set, and A and B are infinite subsets of U. Answer the following questions with a brief explanation.

4. Let U- (1. 2. 3, 9]. Give examples to illustrate the following facts (a) If A c Band B c C, then A CC (c) If U-AU Band An B=, it always follows that A-U-B (d) A x (B n C) = (A B) n (A C)