:- module require_bug.

:- interface.

:- pred foo(int::out, int::out) is failure.

:- implementation.

foo(Y, Z) :-
	require_det true,
	require_semidet semidet_succeed,
	require_multi (Y = 1; Y = 2),
	require_nondet ((Z = 1; Z = 2), semidet_succeed),
	require_failure false.