proposition: Lemma normN x : norm (- x) = norm x.
proof: Proof. by rewrite -mulN1r normM {1}/norm iJ mulrN -expr2 sqrtK opprK mul1r. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun ssrnat eqtype seq choice) mathcomp(div fintype path bigop finset prime order ssralg) mathcomp(poly polydiv mxpoly generic_quotient countalg) mathcomp(ssrnum closed_field ssrint archimedean rat intdiv) mathcomp(algebraics_fundamentals)