proposition: Lemma mulmxKp p m n (B : 'M[F]_(m, n)) : row_free B -> cancel ((@mulmx _ p _ _)^~ B) (mulmx^~ (pinvmx B)).
proof: Proof. by move=> ? A; rewrite -mulmxA mulmxVp ?mulmx1. 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)