English
Taking i elements from sz.splitLengths l equals splitting sz into i parts then taking i from l.
Русский
Взятие i элементов из sz.splitLengths l эквивалентно взятию i частей sz.splitLengths l от l.
LaTeX
$$$ (sz.splitLengths l).take i = (sz.take i).splitLengths l $$$
Lean4
theorem take_splitLength (i : ℕ) : (sz.splitLengths l).take i = (sz.take i).splitLengths l :=
by
induction i generalizing sz l
case zero => simp
case succ i hi =>
cases sz
· simp
· simp only [splitLengths_cons, take_succ_cons, hi]