proposition: Lemma eq_mxblock A_ B_ : (forall i j, A_ i j = B_ i j) -> (\mxblock_(i, j) A_ i j = \mxblock_(i, j) B_ i j).
proof: Proof. by move=> /eq_mxblockP. 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)