proposition: Lemma sqrte_sqr x : sqrte (x ^+ 2) = `|x|%E.
proof: Proof. by case: x => [x||//]; rewrite /expe/= ?sqrtr_sqr// mulyy. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra) signed