5.6 Define the predicate unifiable(List1, Term, List2) where List2 is the list of all the members of List1 that match Term, but are not instantiated by this matching. For example: ?- unifiable([X,

b, t(Y)], t(a), List). List = [X, t(Y)] Note that X and Y have to remain uninstantiated although the matching with t

(a) does cause their instantiation. Hint: Use not( Term1 = Term2). If Term1 = Term2 succeeds then not( Term1 = Term2) fails and the resulting instantiation is undone!