集合定律 逻辑定律 Let X denote a set,and A,B,and C denote subsets of X.Then (DeMorgan's laws) -(PVQ)分（一PA-Q): 1.0≤A and A≤A. 一(PAQ)分（一PVQ)月 2.(A=A. (Distributive property)(PA(QVR))((PAQ)V(PAR)); 3.AU0=A. (PV(QAR))((PVQ)A(PVR)); 4.A∩0=0. (Double negation) (一P)台P 5.A∩A=A. 6.AUA=A. 7.AnB=BnA.(Commutative property) (Associative property) (PA(QAR))((PAQ)AR); 8.AUB=BUA.(Commutative property) (PV(QVR)÷(PVQ)VR); 9.(AUB)UC=AU(BUC).(Associative property) 10.(AnB)nC=An(BnC).(Associative property) (Commutative property)(PAQ)分(QAP)方 11.A∩B≤A. (PVQ)(QVP). 12.A≤AUB. 13.AU(BnC)=(AUB)(AUC).(Distributive property) 14.A∩(BUC=(A∩B)U(A∩C).(Distributive propertu 15.X(A UB)=(XA)n(X\B).(DeMorgan's law) (When X is the universe we also write (AUB)=Acn Be.) 16.X(AnB)=(XA)U(X\B).(DeMorgan's law) (When X is the universe we also write (AnB)=AcU Be.) 17.A\B=A∩B.集合定律 逻辑定律