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 store_similar_chunks:
forall chunk1 chunk2 v1 v2 m b ofs,
encode_val chunk1 v1 = encode_val chunk2 v2 ->
align_chunk chunk1 = align_chunk chunk2 ->
store chunk1 m b ofs v1 = store chunk2 m b ofs v2.