proposition: Lemma ler01 : 0 <= 1 :> R.
proof: Proof. have n1_nz: `|1 : R| != 0 by apply: contraNneq (@oner_neq0 R) => /normr0_eq0->. by rewrite ger0_def -(inj_eq (mulfI n1_nz)) -normrM !mulr1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)