proposition: Lemma mxrank_map m n (A : 'M_(m, n)) : \rank A^f = \rank A.
proof: Proof. by rewrite mxrankE Gaussian_elimination_map. 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)