fact: Definition is_list (x: Vertex) : Prop := exists p, valid_path g p /\ forall y, reachable g x y -> exists (py: path), unique (fun pa => g |= pa is x ~o~> y satisfying (fun _ => True)) py /\ Subpath g py p.
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