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 range_perm_storebytes: forall m1 b ofs bytes, range_perm m1 b ofs (ofs + Z.of_nat (length bytes)) Cur Writable -> { m2 : mem | storebytes m1 b ofs bytes = Some m2 }.