proposition: Lemma genmx1 n : <<1%:M : 'M_n>>%MS = 1%:M.
proof: Proof. rewrite unlock; case/andP: (chooseP (@genmx_witnessP n n 1%:M)) => _ /eqP. by rewrite qidmx_eq1 row_full_unit unitmx1 => /eqP. 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)