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.

Theorem load_storebytes_other: forall chunk b' ofs', b' <> b \/ ofs' + size_chunk chunk <= ofs \/ ofs + Z.of_nat (length bytes) <= ofs' -> load chunk m2 b' ofs' = load chunk m1 b' ofs'.