coerce_void.m:010: In predicate `main'/2:
coerce_void.m:010:   warning: unresolved polymorphism.
coerce_void.m:010:   The variables with unbound types were:
coerce_void.m:010:     V_8: list.list(T)
coerce_void.m:010:     List: list.list(T)
coerce_void.m:010:   The unbound type variables will be implicitly bound to the
coerce_void.m:010:   builtin type `void'.
For more information, recompile with `-E'.