+ intros. xomega.
+ induction 1.
- apply Mem.nextblock_storebytes in H;
rewrite H; xomega.
- apply Mem.nextblock_alloc in H.
rewrite H. clear. xomega.
- apply nextblock_freelist in H.
rewrite H; xomega.
- xomega.
Qed.

Lemma ple_load m ch a v
(LD: Mem.loadv ch m a = Some v)
m1 (PLE: perm_lesseq m m1):
Mem.loadv ch m1 a = Some v.