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 compat_pointer_chunks_true:
forall chunk1 chunk2,
(chunk1 = Mint32 \/ chunk1 = Many32 \/ chunk1 = Mint64 \/ chunk1 = Many64) ->
(chunk2 = Mint32 \/ chunk2 = Many32 \/ chunk2 = Mint64 \/ chunk2 = Many64) ->
quantity_chunk chunk1 = quantity_chunk chunk2 ->
compat_pointer_chunks chunk1 chunk2.