... l) , Q2(X21, X 2 , , X 2m 2) , , Qr(Xrl, X r2, , Xrmr), e p ỳng nu cỏc biu thc: Q1(C11, C 12, , Clml)AQ2(C21, C 22, , C2m2)A AQr(Crl, Cr2, , Crmr)Ae 135 C ú giỏ tr ỳng, Literal Qi(Cil, Ci2, , Cimi) ... h c s hay quan h suy din Mi Ai (i = 1, 2, , n) l hng s hay tờn bin 2) Mt lut DATALOG cú dng: P(X1, X , , Xn) Q 1(X 11, X I , , X lm l), Q 2( X 21 , X 2 , ,X m ), , Qr(Xrl, X r2, , Xrtnr), e ú: ... bin c thay bng hng s Ca(M , 123 ) < - Gitiờn(H N i, 123 , M, W), w> 120 0 Tuy nhiờn, nu thay X bng hng s 123 v 333 thỡ khụng c Ca(M, 123 ) < - Gitiờn(H N i, 333, M, W), w> 120 0 => sai nh ngha ; H in...