proposition: Lemma map_kermx m n (A : 'M_(m, n)) : (kermx A)^f = kermx A^f.
proof: Proof. by rewrite !map_mxM map_invmx map_col_ebase -mxrank_map map_copid_mx. 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)