proposition: Lemma oiso2_vset (G H : pre_graph) (h : G ⩭2 H) x : x \in vset G -> h x \in vset H.
proof: Proof. case: h => /= isG isH h /= xG. rewrite /vfun_of vfun_bodyE. exact: valP. Qed.
imports: Coq(Relation_Definitions Morphisms RelationClasses) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij equiv) GraphTheory(setoid_bigop structures pttdom mgraph mgraph2) GraphTheory(rewriting open_confluence finmap_plus)