proposition: Lemma detM : forall (n : pos_nat) (A B : 'M_n), \det (A *m B) === \det A * \det B.
proof: Proof. move=> n; exact: det_mulmx. Qed.
imports: ssreflect ssrbool ssrfun eqtype ssrnat seq choice fintype finfun bigops ssralg groups perm zmodp morphisms Ring RingClass bigopsClass Setoid Morphisms