Answers

2016-07-13T05:26:46+08:00
A=2n =2.2.2.2 =16 A={a},{b},{c},{d},{a,b},{a,c},{a,d}, {bc},{b,d},{c,d},{a,b,c},{a,b,d},{a,c,d},{b,c,d},{a,b,c,d},{}
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