proposition: Lemma mxrank_fullrowsub : \rank (rowsub frf A) = n.
proof: Proof. exact/eqP/fullrowsub_full. 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)