proposition: Lemma mulcJ_ge0 (x : R[i]) : 0 <= x * x^*%C.
proof: Proof. by move: x=> [a b]; simpc; rewrite mulrC addNr eqxx addr_ge0 ?sqr_ge0. 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)