proposition: Lemma mxblock_const a : \mxblock_(i, j) (const_mx a : 'M[V]_(p_ i, q_ j)) = const_mx a.
proof: Proof. by apply/matrixP=> i j; rewrite !mxE. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype finfun bigop finset fingroup perm order) mathcomp(div prime binomial ssralg countalg finalg zmodp)