proposition: Lemma col_row_permC s t A : col_perm s (row_perm t A) = row_perm t (col_perm s A).
proof: Proof. by apply/matrixP=> i j; rewrite !mxE. 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)