no goals
ι : Type ?u.113338
α : Type u
β : Type v
γ : Type w
δ : Type x
l₁ l₂ : List α
a head✝ : α
as : List α
x✝¹ : 0 < length (head✝ :: as)
x✝ : 0 ≤ 0
⊢ insertNth 0 a (removeNth (head✝ :: as) 0) = removeNth (insertNth (0 + 1) a (head✝ :: as)) 0
simp [removeNth, insertNth]