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

Lemma ghost_of_join:
forall phi1 phi2 phi3,
join phi1 phi2 phi3 ->
join (ghost_of phi1) (ghost_of phi2) (ghost_of phi3).