(* Definition split_rmap (m: rmap) : rmap * rmap := (proj1_sig (make_rmap _ (split_rmap_valid1 m) (level m) (split_rmap_ok1 m)), proj1_sig (make_rmap _ (split_rmap_valid2 m) (level m) (split_rmap_ok2 m))). *)

Lemma VALspec_range_share_join:
forall sh1 sh2 sh n p,
readable_share sh1 ->
readable_share sh2 ->
join sh1 sh2 sh ->
VALspec_range n sh1 p *
VALspec_range n sh2 p =
VALspec_range n sh p.