(** ** Properties of [storebytes]. *)
(** [storebytes] preserves block validity, permissions, access validity, and bounds. Moreover, a [storebytes] succeeds if and only if we have write permissions on the addressed memory area. *)

Axiom storebytes_valid_block_2:
forall m1 b ofs bytes m2, storebytes m1 b ofs bytes = Some m2 ->
forall b', valid_block m2 b' -> valid_block m1 b'.