proposition: Lemma lt1mx m n (A : 'M_(m, n)) : (1%:M < A)%MS = false.
proof: Proof. by rewrite /ltmx submx1 andbF. 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 finalg zmodp matrix)