pushOnce : Meta -> Meta
pushOnce m = M.exec pushSingleLinkedStackCS m

popOnce : Meta -> Meta
popOnce m = M.exec popSingleLinkedStackCS m

push-pop-type : Meta -> Set₁
push-pop-type meta =
    M.exec (M.csComp  (M.cs popOnce) (M.cs pushOnce)) meta ≡ meta