proposition: Lemma normE x y : y ^+ 2 = x -> norm x = y * conj y.
proof: Proof. rewrite /norm => /sqrtE[b /(canLR (signrMK b)) <-]. by rewrite !rmorphM /= rmorph_sign mulrACA -mulrA signrMK. 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)