different/2 - does a pure, determinate definition exist?

Question

different(Xs, Ys) :-
   member(X, Xs),
   non_member(X, Ys).
different(Xs, Ys) :-
   member(Y, Ys),
   non_member(Y, Xs).

While this definition usi

Answer 1

Let's take it to the limit---by the help of list_nonmember_t/3, exists_in_t/3, and or_/2!

some_absent_t(Xs,Ys,Truth) :-
   exists_in_t(list_nonmember_t(Ys),Xs,Truth).

different(Xs,Ys) :-
   or_(some_absent_t(Xs,Ys),
       some_absent_t(Ys,Xs)).