proposition: Lemma mulmxBl m n p (A1 A2 : 'M[R]_(m, n)) (B : 'M_(n, p)) : (A1 - A2) *m B = A1 *m B - A2 *m B.
proof: Proof. by rewrite mulmxDl mulNmx. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype finfun bigop finset fingroup perm order) mathcomp(div prime binomial ssralg countalg finalg zmodp)