proposition: Lemma acyclic_nil_path: forall g p, acyclic_path g (p, nil).
proof: Proof. intros. unfold acyclic_path. simpl. apply NoDup_one. Qed.
imports: Coq.Logic.ProofIrrelevance Coq.micromega.Lia CertiGraph.lib.Coqlib CertiGraph.lib.EnumEnsembles CertiGraph.lib.List_ext CertiGraph.lib.EquivDec_ext CertiGraph.graph.graph_model Coq.Lists.List Coq.Lists.ListDec