proposition: Lemma iso_of_oiso (G H : pre_graph) (graph_G : is_graph G) (graph_H : is_graph H) : G ⩭2 H -> pack G ≃2 pack H.
proof: Proof. case => graph_G' graph_H' I. transitivity (pack G graph_G'); first exact: pack_irrelevance. apply: iso2_comp I _. exact: pack_irrelevance. 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)