Proof with eauto with renamings id_renamings val_renamings.
intros.
constructor; constructor;
eauto with id_renamings; unfold id_ren; intros;
repeat match goal with
| [H: context[valid_block_dec ?M ?B] |- _] =>
destruct (valid_block_dec M B); simpl in *
| [H: _ = Some _ |- _] => inv H; clear H
end; auto.
now apply po_refl.
destruct (ZMap.get ofs (Mem.mem_contents m) # b2) eqn:Hget;
constructor.
destruct v0; constructor.
specialize (H _ v _ _ Hget).
simpl in H.
destruct (valid_block_dec m b); simpl; tauto.
Qed.

Lemma mf_align :
forall (m : mem) (f : memren) (b1 b2 : block) (delta : Z) (chunk : memory_chunk)
(ofs : Z) (p : permission),
f b1 = Some b2 ->
Mem.range_perm m b1 ofs (ofs + size_chunk chunk) Max p ->
(align_chunk chunk | 0%Z)%Z.