:- module create_test_unification.

:- interface.

:- type fruit
    --->    apple
    ;       banana
    ;       cherry.

:- inst ab == bound(apple ; banana).

:- pred test_unification(fruit::in(I =< ab), int::out) is semidet.

:- implementation.

test_unification(X, Y) :-
    require_complete_switch [X]
    (
        X = apple,
        Y = 42
    ;
        X = banana,
        fail
    ).