proposition: Lemma sqrtK x: sqrt x ^+ 2 = x.
proof: Proof. rewrite /sqrt; case: sig_eqW => /= y ->. by rewrite !big_ord_recl big_ord0 /= mulr1 mul0r !addr0. 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)