English
The restriction of the trimmed measure to a set s equals the trimmed restriction: (μ.trim hm).restrict s = (μ.restrict s).trim hm.
Русский
Ограничение обрезанной меры на множество s равно обрезке ограниченной меры: (μ.trim hm).restrict s = (μ.restrict s).trim hm.
LaTeX
$$$(μ.Trim hm).restrict s = (μ.restrict s).trim hm.$$$
Lean4
theorem restrict_trim (hm : m ≤ m0) (μ : Measure α) (hs : @MeasurableSet α m s) :
@Measure.restrict α m (μ.trim hm) s = (μ.restrict s).trim hm :=
by
refine @Measure.ext _ m _ _ (fun t ht => ?_)
rw [@Measure.restrict_apply α m _ _ _ ht, trim_measurableSet_eq hm ht, Measure.restrict_apply (hm t ht),
trim_measurableSet_eq hm (@MeasurableSet.inter α m t s ht hs)]