proposition: Lemma block_mxKdl : dlsubmx A = Adl.
proof: Proof. by rewrite /dlsubmx col_mxKd row_mxKl. 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)