English
Let i, j ∈ Fin(m) and h with m ≤ n. Then the image of the interval Ioo i j under castLE h equals Ioo (castLE h i) (castLE h j).
Русский
Пусть i, j ∈ Fin(m) и h с m ≤ n. Тогда образ интервала Ioo(i, j) под castLE(h) равен Ioo(castLE(h)i, castLE(h)j).
LaTeX
$$$castLE(h) '' Ioo i j = Ioo (castLE(h) i) (castLE(h) j)$$$
Lean4
@[simp]
theorem image_castLE_Ioo (i j : Fin m) (h : m ≤ n) : castLE h '' Ioo i j = Ioo (castLE h i) (castLE h j) :=
val_injective.image_injective <| by simp [image_image]