proposition: Lemma h_mergeE (x: F): h_merge (\pi x) = \pi h x.
proof: Proof. by rewrite /=quot_bijE quot_sameE. Qed.
imports: Coq(Morphisms RelationClasses) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij) GraphTheory(equiv digraph setoid_bigop structures)