proposition: Lemma positive_of_digits_inj : forall l l' p p', List.length l = List.length l' -> positive_of_digits l p = positive_of_digits l' p' -> l = l' /\ p = p'.
proof: Proof. induction l; destruct l'; intros; try discriminate; auto. simpl in *. do 2 break_match; try discriminate; solve [ find_inversion; find_apply_hyp_hyp; break_and; subst; auto ]. Qed.
imports: Coq(ZArith) Coq(FMapInterface FMapPositive) Coq(FMapList FMapFacts) Coq(String Ascii List) StructTact(StructTactics StringOrders)