// example 5.1//
clc
//clears the screen//
clear
//clears all existing variables//
disp("we can DUAL the given equation as : ");
disp('X= AB''+BC''+CD''' );
disp(' Therefore, SO X'' = (A+B'')(B+C'')(C+D'')' );
disp('this says that output Y=X''=(A+B'')(B+C'')(C+D'')' );