proposition: Lemma scalar_productZL (q r: Plane) (t: R): scalar_product (t *: q) r = t * scalar_product q r.
proof: Proof. by rewrite /scalar_product /= -!mulrA -mulrDr. Qed.
imports: axiomsKnuth mathcomp(all_ssreflect ssralg matrix ssrnum vector reals) mathcomp(normedtype order) mathcomp.algebra_tactics(ring) mathcomp.zify(zify)