{-# LANGUAGE Haskell2010 #-}
{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE FlexibleInstances #-}
unit user where
    signature Map where
        class Key k
        instance Key String
    module User where import Map
unit ordmap where
    module Map(Key) where type Key = Ord
unit main where
    dependency user[Map=ordmap:Map] (User as User.Ord)