proposition: Lemma tl_app: forall (l1 l2: list Z), 0 < Zlength l1 -> tl (l1 ++ l2) = tl l1 ++ l2.
proof: Proof. intros. destruct l1; trivial. inversion H. Qed.
imports: Coq.Lists.List Coq.micromega.Lia Coq.Sorting.Permutation Coq.ZArith.ZArith_base Coq.ZArith.Zcomplements Coq.Logic.FunctionalExtensionality CertiGraph.lib.Coqlib CertiGraph.lib.EquivDec_ext VST.zlist.sublist VST.zlist.list_solver