Hello, Given this program: ------------------------------------------------------------ {-# LANGUAGE Rank2Types #-} newtype Region s a = Region a unRegion :: forall a s. Region s a -> a unRegion (Region x) = x runRegionPointfull :: forall a. (forall s. Region s a) -> a runRegionPointfull r = unRegion r ------------------------------------------------------------ Is it possible to write the rank-2 typed function 'runRegionPointfull' in pointfree style? Unfortunately the following doesn't typecheck: runRegionPointfree :: forall a. (forall s. Region s a) -> a runRegionPointfree = unRegion Couldn't match expected type `forall s. Region s a' against inferred type `Region s a1' In the expression: unRegion In the definition of `runRegionPointfree': runRegionPointfree = unRegion Why can't the typechecker match `forall s. Region s a' and `Region s a1'? Thanks, Bas