4. Suppose you wanted ; –) and :0 to be the elements of a set S. (a) How could you indicate this? In particular, how would you convey to someone else that the elements of S are ; -) and :0, and not some other elements? (b) Describe in words how you would indicate the elements of a set.

1) Finite Cardinalities A. For any two sets, is this statement true: n(AUB)=n(A)+n(B) - n(ANB) B. For any two sets, is this statement true: n(AUB)=n(A)+n(B)? Explain. C. Is it possible for n(ANB)=0? Explain. D. Is it possible that n(AUB)=0 and n(ANB)=3? Explain. E. Is it possible that n(AUB)=3 and n(ANB)=0? Explain. stions:

1. Set Notation a. Write in set builder notation: A = {7, 8, 9, 10, ...} b. Is it true that 11 e A? Why or why not? c. Write in set builder notation: D = {7, 8, 9, 10}