fact: Definition cent_mx_fun (B : 'M[F]_n) := R *m lin_mx (mulmxr B \- mulmx B).
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)