proposition: Lemma num_real (R : realDomainType) (x : R) : x \is real.
proof: Proof. exact: le_total. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)