proposition: Lemma ReE z : 'Re z = (z + z^*) / 2%:R.
proof: Proof. by rewrite ['Re _]unlock. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)