proposition: Lemma swap_sym (p q : Plane) : scalar_product (swap p) q = scalar_product p (swap q).
proof: Proof. by rewrite/scalar_product/swap/=; ring. Qed.
imports: axiomsKnuth mathcomp(all_ssreflect ssralg matrix ssrnum vector reals) mathcomp(normedtype order) mathcomp.algebra_tactics(ring) mathcomp.zify(zify)