fact: Definition capmx_gen F m1 m2 n (A : 'M[F]_(m1, n)) (B : 'M_(m2, n)) := lsubmx (kermx (col_mx A B)) *m A.
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)