proposition: Lemma scalerMzl a v n : (a *: v) *~ n = (a *~ n) *: v.
proof: Proof. by rewrite -mulrzl -scaler_int scalerA. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(fintype finfun bigop order ssralg countalg ssrnum) mathcomp(poly)