Mercury/int0s/instances_pc.int0:005: Error: inconsistent instance declaration
Mercury/int0s/instances_pc.int0:005:   for typeclass `instances_pc.foo'/2 with
Mercury/int0s/instances_pc.int0:005:   functional dependency `(A -> B)'.
instances_pc.instances_pc_helper_1.m:019: Here is the conflicting instance.