proposition: Lemma Re_rect : {in real &, forall x y, 'Re (x + 'i * y) = x}.
proof: Proof. move=> x y Rx Ry; rewrite /= raddfD /= (Creal_ReP x Rx). by rewrite ReMr // Re_i mul0r addr0. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)