unit p where
    signature A where
        data A
        neg :: A -> A
    module P where
        import A
        f :: A -> A
        f = neg . neg

unit r where
    module A where
        type A = Bool
        neg :: A -> A
        neg = not

unit q where
    dependency p[A=r:A]
    module M where
        import P
        g :: Bool
        g = f True