proposition: Lemma exprzMzl x m n (ux : x \is a GRing.unit) (um : m%:~R \is a @GRing.unit R): (x *~ m) ^ n = (m%:~R ^ n) * x ^ n :> R.
proof: Proof. rewrite -[x *~ _]mulrzl exprMz_comm //; exact/commr_sym/commr_int. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(fintype finfun bigop order ssralg countalg ssrnum) mathcomp(poly)