fact: Variables (m n : nat) (V W : 'M[F]_(m, n)) (f g : 'M[F]_n).
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)