proposition: Lemma reachable_by_path_head: forall (g: Gph) p n1 n2 P, g |= p is n1 ~o~> n2 satisfying P -> phead p = n1.
proof: Proof. intros. destruct H as [[? _] _]. trivial. 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