Definition kv_stable {X} (m : Poram X) : Prop :=
forall s, poram_lift (state_equiv s) (state_equiv s) triv m.

(* Specifications: *)
Lemma mreturn_stable {X} (x : X) : kv_stable (mreturn x).
Lemma bind_stable {X Y} (m : Poram X) (f : X -> Poram Y) :
kv_stable m ->
(forall x, kv_stable (f x)) ->
kv_stable (x <- m;; f x).
Lemma read_stable k' :
kv_stable (read k').