cases n with
| zero =>
  simp
  refine le_trans (norm_innerSL_le_one ℝ) (by simp)
| succ n =>
  rw [iteratedFDeriv_const_of_ne]
  . change ‖0‖ ≤ _
    simp
  . simp
case succ
𝕜 : Type u_1
𝕜' : Type u_2
D : Type u_3
E : Type u_4
F : Type u_5
G : Type u_6
inst✝² : NormedAddCommGroup E
hE : InnerProductSpace ℝ E
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace ℝ F
x : E
n : ℕ
⊢ ‖iteratedFDeriv ℝ n (fun y => innerSL ℝ) x‖ ≤ 1 + ‖x‖
no goals