proposition: Lemma sfunX f n : f ^+ n =1 (fun x => f x ^+ n).
proof: Proof. by move=> x; elim: n => [|n IHn]//; rewrite !exprS sfunM/= IHn. Qed.
imports: HB(structures) mathcomp(all_ssreflect ssralg ssrnum ssrint interval finmap) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality fsbigop ) signed reals ereal topology normedtype sequences real_interval esum measure lebesgue_measure numfun