proposition: Lemma normr_nat n : `|n%:R : R| = n%:R.
proof: Proof. exact: ger0_norm. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)