proposition: Lemma im_efun_of (F G : pre_graph) (i : F ⩭2 G) : {in eset F, forall e, efun_of i e \in eset G}.
proof: Proof. move => e eF. rewrite /= efun_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)