main :-
	V1=V1-X1, W1=V1, unify_with_occurs_check(V1,W1), write(ok1), nl, fail.
main :-
	V2=V2-X2, W2=W2-X2, unify_with_occurs_check(V2,W2), write(ok2), nl, fail.
main :-
	V3=V3-X3, W3=W3-Y3, unify_with_occurs_check(V3,W3), write(ok3), nl, fail.
main :-
	V4=V4-X4, W4=W4-s(X4), \+ unify_with_occurs_check(V4,W4), write(ok4), nl, fail.
main :-
	V5=V5-X5, unify_with_occurs_check(V5,W5), write(ok5), nl, fail.
main :-
	\B1=A1, C1=[B1|A1], acyclic_term([C1,C1]), write(ok6), nl, fail.
main :-
	\D2=A2, C2=[B2|A2], \+ unify_with_occurs_check(B2,[C2|A2]), write(ok7), nl, fail.
main.

:- initialization(main).