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.Arith.Arith CertiGraph.lib.Coqlib CertiGraph.lib.EnumEnsembles CertiGraph.lib.EquivDec_ext CertiGraph.lib.List_ext CertiGraph.graph.graph_model CertiGraph.graph.path_lemmas CertiGraph.graph.subgraph2 CertiGraph.graph.MathGraph CertiGraph.graph.FiniteGraph CertiGraph.graph.reachable_computable Coq.Lists.List