English
For the iUnion-type lemma, we have a bound on the content over a union of indexed cylinders by the sum over indices.
Русский
Для леммы iUnion имеем ограничение содержания на объединение цилиндров по индексам суммой содержания по индексам.
LaTeX
$$$\forall n,\ \operatorname{projectiveFamilyContent} hP (\bigcup_{i=0}^{n} s_i) \le \sum_{i=0}^{n} \operatorname{projectiveFamilyContent} hP (s_i)$$$
Lean4
/-- `unitInterval.symm` bundled as a measurable equivalence. -/
@[simps]
def symmMeasurableEquiv : I ≃ᵐ I where
toFun := σ
invFun := σ
left_inv := symm_symm
right_inv := symm_symm
measurable_toFun := measurable_symm
measurable_invFun := measurable_symm