【正文】
??c)?(a?d) 6 BDD a b c d 0 c d b c d d 1 c d (a?b)?(?b??c)?(a?d) 7 BDD a b c d 0 c d b c 1 c d (a?b)?(?b??c)?(a?d) 8 BDD a b c d 0 c d b c 1 c d (a?b)?(?b??c)?(a?d) 9 BDD a b c c d b c c 0 1 (a?b)?(?b??c)?(a?d) 10 BDD a b c c d b c c 0 1 (a?b)?(?b??c)?(a?d) 11 BDD a b c d b c 0 1 (a?b)?(?b??c)?(a?d) 12 BDD a b c d d 0 0 0 0 c d d 0 1 0 0 b c d d 1 1 1 1 c d d 1 1 0 0 (a?b)?(