proposition: Lemma inputOrder_wf': forall len i, lengthInput i <= len -> Acc inputOrder i.
proof: Proof. induction len; intros; constructor; intros; unfold inputOrder in * |-. + exfalso. intuition. + apply IHlen. intuition. Qed.
imports: Coq.Classes.Morphisms Coq.micromega.Lia Coq.Logic.FunctionalExtensionality CertiGraph.lib.Coqlib CertiGraph.lib.EquivDec_ext CertiGraph.lib.EnumEnsembles CertiGraph.lib.List_ext CertiGraph.graph.graph_model CertiGraph.graph.path_lemmas CertiGraph.graph.graph_gen CertiGraph.graph.FiniteGraph