{-# LANGUAGE TypeFamilies #-}
unit f where
    module F where
        type family F a
unit p where
    dependency f
    signature A where
        data T
    module P where
        import F
        import A
        type instance F T = Bool
unit q where
    dependency p[A=<B>]
    dependency f
    module Q where
        import F
        import B
        import P
        x :: F T
        x = True