Theorem: controlled_sum_of_mem_closure_range
File: Mathlib/Analysis/Normed/Group/Basic.lean

Proof steps:
state_before: 𝓕 : Type u_1
𝕜 : Type u_2
α : Type u_3
ι : Type u_4
κ : Type u_5
E : Type u_6
F : Type u_7
G : Type u_8
inst✝¹ : SeminormedCommGroup E
inst✝ : SeminormedCommGroup F
a a₁ a₂ b✝ b₁ b₂ : E
r r₁ r₂ : ℝ
j : E →* F
b : F
hb : b ∈ closure ↑j.range
f : ℕ → ℝ
b_pos : ∀ (n : ℕ), 0 < f n
⊢ ∃ a,
    Tendsto (fun n => ∏ i ∈ range (n + 1), j (a i)) atTop (𝓝 b) ∧
      ‖j (a 0) / b‖ < f 0 ∧ ∀ (n : ℕ), 0 < n → ‖j (a n)‖ < f n
state_after: case intro.intro.intro.intro
𝓕 : Type u_1
𝕜 : Type u_2
α : Type u_3
ι : Type u_4
κ : Type u_5
E : Type u_6
F : Type u_7
G : Type u_8
inst✝¹ : SeminormedCommGroup E
inst✝ : SeminormedCommGroup F
a a₁ a₂ b✝ b₁ b₂ : E
r r₁ r₂ : ℝ
j : E →* F
b : F
hb : b ∈ closure ↑j.range
f : ℕ → ℝ
b_pos : ∀ (n : ℕ), 0 < f n
v : ℕ → F
sum_v : Tendsto (fun n => ∏ i ∈ range (n + 1), v i) atTop (𝓝 b)
v_in : ∀ (n : ℕ), v n ∈ j.range
hv₀ : ‖v 0 / b‖ < f 0
hv_pos : ∀ (n : ℕ), 0 < n → ‖v n‖ < f n
⊢ ∃ a,
    Tendsto (fun n => ∏ i ∈ range (n + 1), j (a i)) atTop (𝓝 b) ∧
      ‖j (a 0) / b‖ < f 0 ∧ ∀ (n : ℕ), 0 < n → ‖j (a n)‖ < f n
tactic: obtain ⟨v, sum_v, v_in, hv₀, hv_pos⟩ := controlled_prod_of_mem_closure hb b_pos
state_before: case intro.intro.intro.intro
𝓕 : Type u_1
𝕜 : Type u_2
α : Type u_3
ι : Type u_4
κ : Type u_5
E : Type u_6
F : Type u_7
G : Type u_8
inst✝¹ : SeminormedCommGroup E
inst✝ : SeminormedCommGroup F
a a₁ a₂ b✝ b₁ b₂ : E
r r₁ r₂ : ℝ
j : E →* F
b : F
hb : b ∈ closure ↑j.range
f : ℕ → ℝ
b_pos : ∀ (n : ℕ), 0 < f n
v : ℕ → F
sum_v : Tendsto (fun n => ∏ i ∈ range (n + 1), v i) atTop (𝓝 b)
v_in : ∀ (n : ℕ), v n ∈ j.range
hv₀ : ‖v 0 / b‖ < f 0
hv_pos : ∀ (n : ℕ), 0 < n → ‖v n‖ < f n
⊢ ∃ a,
    Tendsto (fun n => ∏ i ∈ range (n + 1), j (a i)) atTop (𝓝 b) ∧
      ‖j (a 0) / b‖ < f 0 ∧ ∀ (n : ℕ), 0 < n → ‖j (a n)‖ < f n
state_after: case intro.intro.intro.intro
𝓕 : Type u_1
𝕜 : Type u_2
α : Type u_3
ι : Type u_4
κ : Type u_5
E : Type u_6
F : Type u_7
G : Type u_8
inst✝¹ : SeminormedCommGroup E
inst✝ : SeminormedCommGroup F
a a₁ a₂ b✝ b₁ b₂ : E
r r₁ r₂ : ℝ
j : E →* F
b : F
hb : b ∈ closure ↑j.range
f : ℕ → ℝ
b_pos : ∀ (n : ℕ), 0 < f n
v : ℕ → F
sum_v : Tendsto (fun n => ∏ i ∈ range (n + 1), v i) atTop (𝓝 b)
hv₀ : ‖v 0 / b‖ < f 0
hv_pos : ∀ (n : ℕ), 0 < n → ‖v n‖ < f n
g : ℕ → E
hg : ∀ (n : ℕ), j (g n) = v n
⊢ ∃ a,
    Tendsto (fun n => ∏ i ∈ range (n + 1), j (a i)) atTop (𝓝 b) ∧
      ‖j (a 0) / b‖ < f 0 ∧ ∀ (n : ℕ), 0 < n → ‖j (a n)‖ < f n
tactic: choose g hg using v_in
state_before: case intro.intro.intro.intro
𝓕 : Type u_1
𝕜 : Type u_2
α : Type u_3
ι : Type u_4
κ : Type u_5
E : Type u_6
F : Type u_7
G : Type u_8
inst✝¹ : SeminormedCommGroup E
inst✝ : SeminormedCommGroup F
a a₁ a₂ b✝ b₁ b₂ : E
r r₁ r₂ : ℝ
j : E →* F
b : F
hb : b ∈ closure ↑j.range
f : ℕ → ℝ
b_pos : ∀ (n : ℕ), 0 < f n
v : ℕ → F
sum_v : Tendsto (fun n => ∏ i ∈ range (n + 1), v i) atTop (𝓝 b)
hv₀ : ‖v 0 / b‖ < f 0
hv_pos : ∀ (n : ℕ), 0 < n → ‖v n‖ < f n
g : ℕ → E
hg : ∀ (n : ℕ), j (g n) = v n
⊢ ∃ a,
    Tendsto (fun n => ∏ i ∈ range (n + 1), j (a i)) atTop (𝓝 b) ∧
      ‖j (a 0) / b‖ < f 0 ∧ ∀ (n : ℕ), 0 < n → ‖j (a n)‖ < f n
state_after: no goals
tactic: exact
    ⟨g, by simpa [← hg] using sum_v, by simpa [hg 0] using hv₀,
      fun n hn => by simpa [hg] using hv_pos n hn⟩