“复习”几个概念： Literal?Fundamental product?Contained in? E=xz+y'z+xyz'and E2=xz'+x'yz'+xy'z Contained in? Observe that if P is contained in P2.say P2=P*2,then,by the absorption law, P1+P2=P1+P1*Q=P1 Thus,for instance,x+x'y=x“复习”几个概念： Literal？Fundamental product？Contained in? Contained in?