proposition: Lemma eqmx_refl m1 n (A : 'M_(m1, n)) : (A :=: A)%MS.
proof: Proof. by []. 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)