Theorem: MeasureTheory.Submartingale.bddAbove_iff_exists_tendsto
File: Mathlib/Probability/Martingale/BorelCantelli.lean

tactic: set g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
⊢ ∀ᵐ (ω : Ω) ∂μ, BddAbove (Set.range fun n => f n ω) ↔ ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)
state_after: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
⊢ ∀ᵐ (ω : Ω) ∂μ, BddAbove (Set.range fun n => f n ω) ↔ ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)

tactic: have hg : Submartingale g ℱ μ :=
  hf.sub_martingale (martingale_const_fun _ _ (hf.adapted 0) (hf.integrable 0))
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
⊢ ∀ᵐ (ω : Ω) ∂μ, BddAbove (Set.range fun n => f n ω) ↔ ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)
state_after: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
⊢ ∀ᵐ (ω : Ω) ∂μ, BddAbove (Set.range fun n => f n ω) ↔ ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)

tactic: have hg0 : g 0 = 0 := by
  ext ω
  simp only [g, sub_self, Pi.zero_apply]
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
⊢ ∀ᵐ (ω : Ω) ∂μ, BddAbove (Set.range fun n => f n ω) ↔ ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)
state_after: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
⊢ ∀ᵐ (ω : Ω) ∂μ, BddAbove (Set.range fun n => f n ω) ↔ ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)

tactic: have hgbdd : ∀ᵐ ω ∂μ, ∀ i : ℕ, |g (i + 1) ω - g i ω| ≤ ↑R := by
  simpa only [g, sub_sub_sub_cancel_right]
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
⊢ ∀ᵐ (ω : Ω) ∂μ, BddAbove (Set.range fun n => f n ω) ↔ ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)
state_after: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
⊢ ∀ᵐ (ω : Ω) ∂μ, BddAbove (Set.range fun n => f n ω) ↔ ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)

tactic: filter_upwards [hg.bddAbove_iff_exists_tendsto_aux hg0 hgbdd] with ω hω
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
⊢ ∀ᵐ (ω : Ω) ∂μ, BddAbove (Set.range fun n => f n ω) ↔ ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)
state_after: case h
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
⊢ BddAbove (Set.range fun n => f n ω) ↔ ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)

tactic: convert hω using 1
state_before: case h
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
⊢ BddAbove (Set.range fun n => f n ω) ↔ ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)
state_after: case h.e'_1.a
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
⊢ BddAbove (Set.range fun n => f n ω) ↔ BddAbove (Set.range fun n => g n ω)

case h.e'_2.a
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
⊢ (∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)

tactic: ext ω
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
⊢ g 0 = 0
state_after: case h
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
ω : Ω
⊢ g 0 ω = 0 ω

tactic: simp only [g, sub_self, Pi.zero_apply]
state_before: case h
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
ω : Ω
⊢ g 0 ω = 0 ω
state_after: no goals

tactic: simpa only [g, sub_sub_sub_cancel_right]
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
⊢ ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
state_after: no goals

tactic: refine ⟨fun h => ?_, fun h => ?_⟩ <;> obtain ⟨b, hb⟩ := h <;>
refine ⟨b + |f 0 ω|, fun y hy => ?_⟩ <;> obtain ⟨n, rfl⟩ := hy
state_before: case h.e'_1.a
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
⊢ BddAbove (Set.range fun n => f n ω) ↔ BddAbove (Set.range fun n => g n ω)
state_after: case h.e'_1.a.refine_1.intro.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
b : ℝ
hb : b ∈ upperBounds (Set.range fun n => f n ω)
n : ℕ
⊢ (fun n => g n ω) n ≤ b + |f 0 ω|

case h.e'_1.a.refine_2.intro.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
b : ℝ
hb : b ∈ upperBounds (Set.range fun n => g n ω)
n : ℕ
⊢ (fun n => f n ω) n ≤ b + |f 0 ω|

tactic: simp_rw [g, sub_eq_add_neg]
state_before: case h.e'_1.a.refine_1.intro.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
b : ℝ
hb : b ∈ upperBounds (Set.range fun n => f n ω)
n : ℕ
⊢ (fun n => g n ω) n ≤ b + |f 0 ω|
state_after: case h.e'_1.a.refine_1.intro.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
b : ℝ
hb : b ∈ upperBounds (Set.range fun n => f n ω)
n : ℕ
⊢ f n ω + -f 0 ω ≤ b + |f 0 ω|

tactic: exact add_le_add (hb ⟨n, rfl⟩) (neg_le_abs _)
state_before: case h.e'_1.a.refine_1.intro.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
b : ℝ
hb : b ∈ upperBounds (Set.range fun n => f n ω)
n : ℕ
⊢ f n ω + -f 0 ω ≤ b + |f 0 ω|
state_after: no goals

tactic: exact sub_le_iff_le_add.1 (le_trans (sub_le_sub_left (le_abs_self _) _) (hb ⟨n, rfl⟩))
state_before: case h.e'_1.a.refine_2.intro.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
b : ℝ
hb : b ∈ upperBounds (Set.range fun n => g n ω)
n : ℕ
⊢ (fun n => f n ω) n ≤ b + |f 0 ω|
state_after: no goals

tactic: refine ⟨fun h => ?_, fun h => ?_⟩ <;> obtain ⟨c, hc⟩ := h
state_before: case h.e'_2.a
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
⊢ (∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
state_after: case h.e'_2.a.refine_1.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
c : ℝ
hc : Tendsto (fun n => f n ω) atTop (𝓝 c)
⊢ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)

case h.e'_2.a.refine_2.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
c : ℝ
hc : Tendsto (fun n => g n ω) atTop (𝓝 c)
⊢ ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)

tactic: exact ⟨c - f 0 ω, hc.sub_const _⟩
state_before: case h.e'_2.a.refine_1.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
c : ℝ
hc : Tendsto (fun n => f n ω) atTop (𝓝 c)
⊢ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
state_after: no goals

tactic: refine ⟨c + f 0 ω, ?_⟩
state_before: case h.e'_2.a.refine_2.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
c : ℝ
hc : Tendsto (fun n => g n ω) atTop (𝓝 c)
⊢ ∃ c, Tendsto (fun n => f n ω) atTop (𝓝 c)
state_after: case h.e'_2.a.refine_2.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
c : ℝ
hc : Tendsto (fun n => g n ω) atTop (𝓝 c)
⊢ Tendsto (fun n => f n ω) atTop (𝓝 (c + f 0 ω))

tactic: have := hc.add_const (f 0 ω)
state_before: case h.e'_2.a.refine_2.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
c : ℝ
hc : Tendsto (fun n => g n ω) atTop (𝓝 c)
⊢ Tendsto (fun n => f n ω) atTop (𝓝 (c + f 0 ω))
state_after: case h.e'_2.a.refine_2.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
c : ℝ
hc : Tendsto (fun n => g n ω) atTop (𝓝 c)
this : Tendsto (fun k => g k ω + f 0 ω) atTop (𝓝 (c + f 0 ω))
⊢ Tendsto (fun n => f n ω) atTop (𝓝 (c + f 0 ω))

tactic: simpa only [g, sub_add_cancel]
state_before: case h.e'_2.a.refine_2.intro
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
ℱ : Filtration ℕ m0
f : ℕ → Ω → ℝ
ω✝ : Ω
r : ℝ
R : ℝ≥0
inst✝ : IsFiniteMeasure μ
hf : Submartingale f ℱ μ
hbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |f (i + 1) ω - f i ω| ≤ ↑R
g : ℕ → Ω → ℝ := fun n ω => f n ω - f 0 ω
hg : Submartingale g ℱ μ
hg0 : g 0 = 0
hgbdd : ∀ᵐ (ω : Ω) ∂μ, ∀ (i : ℕ), |g (i + 1) ω - g i ω| ≤ ↑R
ω : Ω
hω : BddAbove (Set.range fun n => g n ω) ↔ ∃ c, Tendsto (fun n => g n ω) atTop (𝓝 c)
c : ℝ
hc : Tendsto (fun n => g n ω) atTop (𝓝 c)
this : Tendsto (fun k => g k ω + f 0 ω) atTop (𝓝 (c + f 0 ω))
⊢ Tendsto (fun n => f n ω) atTop (𝓝 (c + f 0 ω))
state_after: no goals