proposition: Lemma ImMir x : 'Im (x * 'i) = 'Re x.
proof: Proof. by rewrite mulrC ImMil. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)