Y(A,B,C,D)= ∑m(0,4,6,8,10,12,14)
= ∑m(0,4,8,12)+ ∑m(,4,6,12,14)+ ∑m(8,10,12,14)
=C’D’+BD’+AD’
Y(A,B,C)=AB+BC’+A’C’
= ∑m(12,13,14,15)+ ∑m(4,5,12,13)+ ∑m(0,1,4,5)
= ∑m(12,13,14,15)+ ∑m(0,1,4,5)
=AB+A’C’
Y(A,B,C,D)= ∑m(0,4,6,8,10,12,14)
= ∑m(0,4,8,12)+ ∑m(,4,6,12,14)+ ∑m(8,10,12,14)
=C’D’+BD’+AD’
Y(A,B,C)=AB+BC’+A’C’
= ∑m(12,13,14,15)+ ∑m(4,5,12,13)+ ∑m(0,1,4,5)
= ∑m(12,13,14,15)+ ∑m(0,1,4,5)
=AB+A’C’