weakenByFA :: (forall t'. Idx aenv t' -> Idx aenv' t') -> OpenFun env aenv t -> OpenFun env aenv' t
weakenByFA k = rebuildFA rebuildOpenAcc (Avar . k)
weakenByFA :: (forall t'. Idx aenv t' -> Idx aenv' t') -> OpenFun env aenv t -> OpenFun env aenv' t
weakenByFA k = rebuildFA rebuildOpenAcc (Avar . k)
weakenByFA k = rebuildFA rebuildOpenAcc (Avar . k)