proposition: Lemma checksum'_checksum'' : forall pairs, checksum' pairs = checksum'' pairs (wzero _).
proof: Proof. unfold checksum', checksum''; intros. rewrite <- fold_left_rev_right, (checksum'_permutation _ _ (Permutation_rev _)). reflexivity. Qed.
imports: Fiat.Common.Coq__8_4__8_5__Compat List Bedrock.Word Coq.ZArith.ZArith Coq.micromega.Psatz NArith NArithRing ZArith ZArithRing Program Coq.micromega.Psatz AlignedByteString Permutation