0 …………… 4、/0 0 0 0 b 3 4 0 b 0 即 4 0010 0 b 001b C 上              = b b a a A 0 1 1 1 0 1 0 0 0 1 0 0 , 3 4 1 2       = C C C C       =               A = a 1 C1 0 0 C2 0 1 1 0 0 a C3 b b 1 1 0 0 C4 即