I have a problem, that I can't do.
Let be a Lebesgue-measurable set of , and let be a point of density (of Lebesgue) for , i.e., for all set Lebesgue-measurable which contains , we have
Let be a sequence . Proof that
where is the distance of from the set .
Can someone help me? Thanks
( denote the measure of Lebesgue.)