proposition: Lemma cnv2dot (F G: graph2): (F · G)° ≃2 G° · F°.
proof: Proof. irewrite (merge_iso2 (union_C F G)). apply merge_same'=>/=. apply eqv_clot_eq; leqv. Qed.
imports: HB(structures) Coq(Setoid Morphisms) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij equiv) GraphTheory(setoid_bigop structures pttdom mgraph ptt)