proposition: Lemma partst u v a of is_test a : (u ∥ v)·a ≡ u ∥ v·a.
proof: Proof. apply cnv_inj. rewrite cnvdot 2!cnvpar cnvdot. by rewrite parC tstpar parC. Qed.
imports: HB(structures) Coq(Setoid Morphisms) mathcomp(all_ssreflect) GraphTheory(edone preliminaries setoid_bigop structures)