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

Lemma resource_at_join:
forall phi1 phi2 phi3 loc,
join phi1 phi2 phi3 ->
join (phi1@loc) (phi2@loc) (phi3@loc).