proposition: Lemma length_ByteString_append : forall bs (bs' : ByteString), length_ByteString (fold_right ByteString_push_char bs' bs) = (8 * (length bs)) + length_ByteString bs'.
proof: Proof. induction bs; eauto. simpl length; rewrite mult_succ_r, plus_comm. intros; rewrite <- plus_assoc, <- IHbs. simpl; rewrite length_ByteString_push_char. omega. Qed.
imports: Fiat.Common.Coq__8_4__8_5__Compat Bedrock.Word Coq.ZArith.ZArith Coq.NArith.NArith Coq.Arith.Arith Coq.Numbers.Natural.Peano.NPeano Coq.Logic.Eqdep_dec Fiat.Narcissus.Common.Specs