proposition: Lemma scale1mx A : 1 *m: A = A.
proof: Proof. by apply/matrixP=> i j; rewrite !mxE mul1r. 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)