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 store_storebytes: forall m1 b ofs chunk v m2, store chunk m1 b ofs v = Some m2 -> storebytes m1 b ofs (encode_val chunk v) = Some m2.