English
The image of the interval Ici i under the castSucc map is the interval Ico i.castSucc (last n).
Русский
Образ интервала Ici i при отображении castSucc равен интервалу Ico i.castSucc (последний элемент n).
LaTeX
$$$ \operatorname{image}(\operatorname{Fin.castSucc})\bigl(\operatorname{Ici} i\bigr) = \operatorname{Ico} i.castSucc (\operatorname{Fin.last} n) $$$
Lean4
@[simp]
theorem image_castSucc_Ici (i : Fin n) : castSucc '' Ici i = Ico i.castSucc (.last n) :=
image_castAdd_Ici ..