proposition: Lemma integrableZl (k : R) f : mu_int f -> mu_int (fun x => k%:E * f x).
proof: Proof. move=> /integrableP[mf foo]; apply/integrableP; split. exact: measurable_funeM. under eq_fun do rewrite abseM. by rewrite ge0_integralZl// ?lte_mul_pinfty//; exact: measurableT_comp. 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