English
Alternate expression for condDistrib with a constant function: condDistrib (fun _ => c) X μ equals the deterministic kernel at c.
Русский
Альтернативное выражение condDistrib для константной функции: condDistrib (функция, возвращающая c) X μ равнаDeterministic ядру в c.
LaTeX
$$$$ \\mathrm{condDistrib}(\\lambda x. c, X, μ) =_{a.e.} \\mathrm{deterministic}(\\lambda x. c). $$$$
Lean4
theorem condDistrib_const (X : α → β) (c : Ω) :
condDistrib (fun _ ↦ c) X μ =ᵐ[μ.map X] Kernel.deterministic (fun _ ↦ c) (by fun_prop) :=
by
have : (fun _ : α ↦ c) = (fun _ : β ↦ c) ∘ X := rfl
rw [this]
filter_upwards [condDistrib_comp_self X (measurable_const (a := c))] with b hb
rw [hb]