proposition: Lemma commr_int (x : R) n : GRing.comm x n%:~R.
proof: Proof. exact/commrMz/commr1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(fintype finfun bigop order ssralg countalg ssrnum) mathcomp(poly)