proposition: Lemma mulrzl x n : n%:~R * x = x *~ n.
proof: Proof. by rewrite mulrzAl mul1r. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(fintype finfun bigop order ssralg countalg ssrnum) mathcomp(poly)