proposition: Lemma unitmx1 : 1%:M \in unitmx.
proof: Proof. by rewrite unitmxE det1 unitr1. 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)