mpj4.m:028: In clause for function `g'/1:
mpj4.m:028:   in function result term of clause head:
mpj4.m:028:   in argument 2 of functor `f/3':
mpj4.m:028:   type error in unification of argument
mpj4.m:028:   and constant `"foo"'.
mpj4.m:028:   argument has type
mpj4.m:028:     int,
mpj4.m:028:   constant `"foo"' has type
mpj4.m:028:     string.
mpj4.m:028:   The partial type assignment was:
mpj4.m:028:     HeadVar__2_2: mpj4.intlist
mpj4.m:028:     L_3: mpj4.intlist
mpj4.m:028:     V_4: int
mpj4.m:028:     V_5: int