proposition: Lemma scalarAr k (x y : V) : k *: (x * y) = x * (k *: y).
proof: Proof. by rewrite mulrC scalerAl mulrC. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)