Unificeren met occurs check

% unify(Term1,Term2) :-
%  Term1 and Term2 are unified. ignoring the occurs check.
unify(X, Y) :-
    var(X),
    var(Y),
    X=Y.
unify(X, Y) :-
    var(X),
    nonvar(Y),
    X=Y.
unify(X, Y) :-
    nonvar(X),
    var(Y),
    X=Y.
unify(X, Y) :-
    nonvar(X),
    nonvar(Y),
    atomic(X),
    atomic(Y),
    X=Y.

unify(X, Y) :-
    nonvar(X),
    nonvar(Y),
    compound(X),
    compound(Y),
    functor(X, F, N),
    functor(Y, F, N),
    unify_args(N, X, Y).

unify_args(N, X, Y) :-
    N>0,
    unify_arg(N, X, Y),
    N1 is N-1,
    unify_args(N1, X, Y).
unify_args(0, _, _).

unify_arg(N, X, Y) :-
    arg(N, X, ArgX),
    arg(N, Y, ArgY),
    unify(ArgX, ArgY).

Je kunt zo vaak indienen als je wenst. Er wordt enkel rekening gehouden met je laatst ingediende oplossing.