Module Rmaps_Lemmas (R0: RMAPS).
Module R := R0.
Hint Resolve (@subp_sepcon _ Join_rmap Perm_rmap Sep_rmap): contractive.

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