proposition: Lemma packK (G : pre_graph) (graph_G : is_graph G) : G ⩭2 open (pack G).
proof: Proof. econstructor. exact: openK. Defined.
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)