proposition: Lemma oarc_remove_edges (G : pre_graph) e x u y E : e \notin E -> oarc G e x u y -> oarc (remove_edges G E) e x u y.
proof: Proof. move => He. by rewrite /oarc /= inE He. Qed.
imports: HB(structures) Coq(Relation_Definitions Morphisms RelationClasses) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij equiv) GraphTheory(setoid_bigop structures pttdom rewriting) GraphTheory(finmap_plus)