cases' lim_x 1 (by linarith) with N hN
u✝ : ℕ → ℝ
l : ℝ
φ : ℕ → ℕ
u : ℕ → ℝ
lim_infinie : tendsto_infinity u
x : ℝ
lim_x : seq_limit u x
⊢ False
case intro
u✝ : ℕ → ℝ
l : ℝ
φ : ℕ → ℕ
u : ℕ → ℝ
lim_infinie : tendsto_infinity u
x : ℝ
lim_x : seq_limit u x
N : ℕ
hN : ∀ n ≥ N, |u n - x| ≤ 1
⊢ False