proposition: Lemma forest_no_self_adjacency: forall g e v, uforest' g -> ~ adj_edge g e v v.
proof: Proof. unfold not; intros. destruct H. destruct H0. destruct H0. apply H in H0. destruct H2; destruct H2; subst v; symmetry in H4; contradiction. Qed.
imports: Coq.Logic.Classical CertiGraph.lib.List_ext CertiGraph.lib.EquivDec_ext CertiGraph.graph.graph_model CertiGraph.graph.graph_relation CertiGraph.graph.path_lemmas CertiGraph.graph.graph_gen CertiGraph.graph.FiniteGraph