Math Sub 跟集合有关问题!希望懂的人解答

speedychaos4UID: 2498902

Let A and B be subsets of a set M and let S_0={A,B}. For i>=0, define S_{i+1} inductively to be the collection of subsets X of M that are of the form CuD, CnD or M-C, where C,D in S_i. Let S= union_{i=0}^{\infty}{S_i}. What is the largest possible number of elements of S?
A. 4
B. 8
C. 15
D. 16
E. S may be infinite

165524802UID: 2471163

16  
A B 把 全集分成了四个部分  A-B, B-A, AnB, S-{AuB},每个几何都可以有这些几何表示 共16种