proposition: Lemma pnatr_eq1 n : (n%:R == 1 :> R) = (n == 1)%N.
proof: Proof. exact: eqr_nat 1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)