proposition: Lemma add_edge_vlabel F x a y u z: F [tst x <- a] ∔ [y, u, z] ≃ F ∔ [y, u, z] [tst x <- a].
proof: Proof. reflexivity. Defined.
imports: Coq(Morphisms RelationClasses) mathcomp(all_ssreflect) GraphTheory(edone finite_quotient preliminaries bij) GraphTheory(equiv digraph setoid_bigop structures)