proposition: Lemma natr_absz i : `|i|%:R = `|i|%:~R :> R.
proof: Proof. by rewrite -abszE. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(fintype finfun bigop order ssralg countalg ssrnum) mathcomp(poly)