Definition compat_pointer_chunks (chunk1 chunk2: memory_chunk) : Prop :=
  match chunk1, chunk2 with
  | (Mint32 | Many32), (Mint32 | Many32) => True
  | (Mint64 | Many64), (Mint64 | Many64) => True
  | _, _ => False
  end.

Lemma load_inj: forall f m1 m2 chunk b1 ofs b2 delta v1, mem_inj f m1 m2 -> load chunk m1 b1 ofs = Some v1 -> f b1 = Some (b2, delta) -> exists v2, load chunk m2 b2 (ofs + delta) = Some v2 /\ Val.inject f v1 v2.