Module R := R.
Hint Resolve (@subp_sepcon _ Join_rmap Perm_rmap Sep_rmap): contractive.
unfold identity_rmap; intros.
rewrite R.unsquash_squash.
simpl.
apply extensionality; intro l.
unfold compose; simpl; auto.
Qed.

Lemma make_rmap': forall f, AV.valid (fun l => res_option (f l)) ->
exists phi: rmap', proj1_sig phi = f.