fact: Definition fullrankfun : 'I_m ^ n := finfun (mxf \o cast_ord (esym (eqP rkA))).
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)