P NP terui@nii.ac.jp http://research.nii.ac.jp/~terui NO V Hartmanis & Stearns1965) V V V / V V V V V V (feasibly computable) V G V guess & check guess check V Guess V 2n guess check V V G G V n n2 V V G V V V V V V n 2n/2 V V n n2 n3 V a,b,c ax+by=c x,y V V a,b,c ax +by=c x,y V V V : V – – V INPUT V yes INPUT N V A N V G G INPUT V V reasonable ) V G |G| c n3 c V M A INPUT A yes V INPUT INPUT feas