proposition: Lemma tr_diag_mx n (d : 'rV_n) : (diag_mx d)^T = diag_mx d.
proof: Proof. by apply/matrixP=> i j /[!mxE]; case: eqVneq => // ->. 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)