傻瓜

1.XY+XY'=X(Y+Y')=X+1=X  ----->右式比左式的邏輯閘變少了

2.XY'+Y=X+Y

證明:XY'+Y*1=XY'+Y(1+X)=XY'+Y+XY=X(Y+Y')+Y=X*1+Y=X+Y

3.X+YZ=(X+Y)(X+Z)

證明:右式=(X+Y)(X+Z)

              =XX+XY+XZ+YZ .......  (for X*X=X )

             =X+XY+XZ+YZ ............(for X=X*1)

            =X*1+XY+XZ+YZ

             =X(1+Y+Z)+YZ  ...............(for  1+X=1  )

            =X*1+YZ=X+YZ

例子:AB'+CD.........SOP型式

        =(AB'+C)(AB'+D)..............(for  把AB'當做X，CD當做YZ)

        =(A+C)(B'+C)(A+D)(B'+D)

4.迪摩根定律:(X+Y)'=X'*Y'  ，(X*Y)'=X'+Y'