no goals
α : Type u
x✝ : ℕ
⊢ length (rotate' [] x✝) = length []
simp
α : Type u
a : α
l : List α
n : ℕ
⊢ length (l ++ [a]) = length (a :: l)
α : Type u
a : α
l : List α
n : ℕ
⊢ length (rotate' (a :: l) (n + 1)) = length (a :: l)
rw [List.rotate', length_rotate' (l ++ [a]) n]
no goals
α : Type u
a : α
l : List α
n : ℕ
⊢ length (l ++ [a]) = length (a :: l)
simp