(arg_tys, body_ty) = splitFunTyExpandingDicts tau_ty
-- The "expanding dicts" part here is important, even for the splitForAll
-- The imported thing might be a dictionary, such as Functor Foo
(arg_tys, body_ty) = splitFunTyExpandingDicts tau_ty
-- The "expanding dicts" part here is important, even for the splitForAll
-- The imported thing might be a dictionary, such as Functor Foo