proposition: Lemma Creal_Re x : 'Re x \is real.
proof: Proof. by rewrite ReE CrealE fmorph_div rmorph_nat rmorphD /= conjCK addrC. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)