A variant of the above program for sublist is defined by the following three rules:

subsequence([XIXs] , [XIYs]) - subsequence(Xs,Ys).

subsequence(Xs, [Y lYs]) - subsequence(Xs,Ys).

subsequence([ ] ,Ys).

Explain why this prolog program has a different meaning from the above picture.

append(Xs, YsXsYs) XsYs is the result of concatenating the lists Xs and Ys. append([ ],Ys, Ys). append( [X/Xs), Ys, [XZs]) append(X,Y,Zs)