proposition: Lemma ltcE : forall x y, (x < y) = (Im y == Im x) && (Re x < Re y).
proof: Proof. by move=> [a b] [c d]. Qed.
imports: HB(structures) mathcomp.ssreflect.ssreflect mathcomp(ssrfun ssrbool eqtype ssrnat seq choice fintype) mathcomp(bigop order ssralg ssrint div ssrnum rat poly closed_field) mathcomp(polyrcf matrix mxalgebra tuple mxpoly zmodp binomial realalg) mathcomp(mxpoly)