fact: Definition skew_vec n i j : 'rV[K]_(n * n) := (mxvec ((delta_mx i j)) - (mxvec (delta_mx j i))).
imports: HB(structures) mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq choice fintype) mathcomp(bigop order ssralg ssrint div ssrnum rat poly closed_field) mathcomp(polyrcf matrix mxalgebra tuple mxpoly zmodp binomial realalg) mathcomp(mxpoly)