weakenByFE :: (forall t'. Idx env t' -> Idx env' t') -> OpenFun env aenv t -> OpenFun env' aenv t
weakenByFE k = rebuildFE (Var . k)
weakenByFE :: (forall t'. Idx env t' -> Idx env' t') -> OpenFun env aenv t -> OpenFun env' aenv t
weakenByFE k = rebuildFE (Var . k)
weakenByFE k = rebuildFE (Var . k)