6.4.8. Declaring data types with explicit constructor signatures¶| ghc.gitlab.haskell.org
6.4.7. Existentially quantified data constructors¶| ghc.gitlab.haskell.org
6.4.20. Arbitrary-rank polymorphism¶| ghc.gitlab.haskell.org
6.4.16. Visible type application¶| ghc.gitlab.haskell.org