English
For α with a countably generated measurable space, the sigma-algebra generated by the n-th partition is contained in the sigma-algebra generated by the (n+1)-st partition: generateFrom (countablePartition α n) ≤ generateFrom (countablePartition α (n+1)).
Русский
Пусть α имеет счетно генерируемое измеримое пространство. Тогда сигма-алгебра, порождаемая n-й частью разбиения, содержится в сигма-алгебре, порождаемой (n+1)-й частью: generateFrom(countablePartition α n) ≤ generateFrom(countablePartition α (n+1)).
LaTeX
$$$$ \\operatorname{generateFrom}(\\operatorname{countablePartition}(\\alpha,n)) \\le \\operatorname{generateFrom}(\\operatorname{countablePartition}(\\alpha,(n+1))). $$$$
Lean4
theorem generateFrom_countablePartition_le_succ (α : Type*) [MeasurableSpace α] [CountablyGenerated α] (n : ℕ) :
generateFrom (countablePartition α n) ≤ generateFrom (countablePartition α (n + 1)) :=
generateFrom_memPartition_le_succ _ _