proposition: Lemma nth_tl {A} n (ls : list A) a : nth n (tl ls) a = nth (S n) ls a.
proof: Proof. destruct ls, n; simpl; reflexivity. Qed.
imports: Fiat.Common.Coq__8_4__8_5__Compat Coq.ZArith.ZArith Coq.Lists.List Coq.Lists.SetoidList Coq.Bool.Bool Fiat.Common Fiat.Common.List.Operations Fiat.Common.Equality Fiat.Common.List.FlattenList Fiat.Common.LogicFacts