Local Open Scope logic.
(******************************************  Basic lemmas about local_facts, isptr, offset_zero  ******************************************)
(******************************************  Lemmas about mapsto and mapsto_.  ******************************************)
Hint Resolve mapsto_local_facts mapsto__local_facts : saturate_local.

Lemma mapsto_isptr: forall sh t v1 v2, mapsto sh t v1 v2 = !! (isptr v1) && mapsto sh t v1 v2.