proposition: Lemma invmx1 : invmx 1%:M = 1%:M.
proof: Proof. by rewrite /invmx det1 invr1 scale1r adj1 if_same. 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)