(* Lemma make_simple_rmap: forall n (f: AV.address -> resource) , AV.valid (fun l => res_option (f l)) -> (forall l, match f l with YES _ _ (SomeP _ _) => False | _ => True end) -> exists phi:rmap, level phi = n /\ resource_at phi = f. *)

Lemma ageN_squash : forall d n rm, le d n ->
ageN d (squash (n, rm)) = Some (squash ((n - d)%nat, rm)).