proposition: Lemma tst_dotC: forall a b : test, a·b ≡ b·a.
proof: Proof. intros. by rewrite /tst_dot eqv_testE -pardot parC pardot. Qed.
imports: HB(structures) Coq(Setoid Morphisms) mathcomp(all_ssreflect) GraphTheory(edone preliminaries setoid_bigop structures)