English
Let f: β → ENNReal be measurable. Then for any measurable s ⊆ β, the function a ↦ ∫⁻ b in s, f b ∂κ a is measurable.
Русский
Пусть f: β → ENNReal измеримо. Тогда для любого измеримого s ⊆ β функция a ↦ ∫⁻ b ∈ s f(b) ∂κ a измерима.
LaTeX
$$$\\text{Measurable}\\left( a \\mapsto \\int⁻ b \\in s \\, f(b) \\, ∂κ a \\right)$$$
Lean4
/-- Posterior of the kernel `κ` with respect to the measure `μ`. -/
noncomputable def posterior (κ : Kernel Ω 𝓧) (μ : Measure Ω) [IsFiniteMeasure μ] [IsFiniteKernel κ] : Kernel 𝓧 Ω :=
((μ ⊗ₘ κ).map Prod.swap).condKernel