@@ -2,6 +2,7 @@
22{-# language BlockArguments #-}
33{-# language ConstraintKinds #-}
44{-# language DataKinds #-}
5+{-# language FlexibleInstances #-}
56{-# language GADTs #-}
67{-# language InstanceSigs #-}
78{-# language MultiParamTypeClasses #-}
@@ -75,3 +76,4 @@ class MapSpec f where
7576
7677type ComposeConstraint :: (a -> Exp b) -> (b -> Constraint) -> a -> Constraint
7778class c (Eval (f a)) => ComposeConstraint f c a
79+instance c (Eval (f a)) => ComposeConstraint f c a