proposition: Lemma endpoint_iso F G (h: iso F G) b e: endpoint b (h.e e) = h (endpoint (h.d e (+) b) e).
proof: Proof. exact: endpoint_ihom. Qed.
imports: Coq(Morphisms RelationClasses) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij) GraphTheory(equiv digraph setoid_bigop structures)