English
For each n, restricting the induced family μ to the interval Iic n yields μ_n; i.e., ind ucedFamily μ (Iic n) = μ n.
Русский
Для каждого n индуцированное семейство μ, ограниченное интервалом Iic n, равно μ_n; то есть inducedFamily μ (Iic n) = μ n.
LaTeX
$$$\\forall n:\\mathbb{N},\\ inducedFamily\\ μ\\ (Iic\\ n) = μ\\ n$$$
Lean4
/-- Given a family of measures `μ : (n : ℕ) → Measure (Π i : Iic n, X i)`, the induced family
equals `μ` over the intervals `Iic n`. -/
theorem inducedFamily_Iic (n : ℕ) : inducedFamily μ (Iic n) = μ n :=
by
rw [inducedFamily, ← measure_cast (sup_Iic n) μ]
congr with x i
rw [restrict₂, cast_pi (by rw [sup_Iic n])]