Corollary field_at_exclusive : forall (cs : compspecs) (sh : Share.t) (t : type) (fld : list gfield) v (p : val),
  sepalg.nonidentity sh -> 0 < sizeof (nested_field_type t fld) -> exclusive_mpred (field_at sh t fld v p).

Lemma ex_data_at_exclusive : forall (cs : compspecs) (sh : Share.t) (t : type) (p : val), sepalg.nonidentity sh -> 0 < sizeof t -> exclusive_mpred (EX v : _, data_at sh t v p).