applyTysD :: SDoc -> Type -> [Type] -> Type     -- Debug version
applyTysD _   orig_fun_ty []      = orig_fun_ty
applyTysD :: SDoc -> Type -> [Type] -> Type
applyTysD _   orig_fun_ty []      = orig_fun_ty
applyTysD _   orig_fun_ty []      = orig_fun_ty