Theorem: MeasureTheory.Submartingale.expected_stoppedValue_mono
File: Mathlib/Probability/Martingale/OptionalStopping.lean

tactic: rw [← sub_nonneg, ← integral_sub', stoppedValue_sub_eq_sum' hle hbdd]
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
⊢ ∫ (x : Ω), stoppedValue f τ x ∂μ ≤ ∫ (x : Ω), stoppedValue f π x ∂μ
state_after: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
⊢ 0 ≤ ∫ (a : Ω), (fun ω => (∑ i ∈ Finset.range (N + 1), {ω | τ ω ≤ i ∧ i < π ω}.indicator (f (i + 1) - f i)) ω) a ∂μ

case hf
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
⊢ Integrable (stoppedValue f π) μ

case hg
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
⊢ Integrable (stoppedValue f τ) μ

tactic: simp only [Finset.sum_apply]
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
⊢ 0 ≤ ∫ (a : Ω), (fun ω => (∑ i ∈ Finset.range (N + 1), {ω | τ ω ≤ i ∧ i < π ω}.indicator (f (i + 1) - f i)) ω) a ∂μ
state_after: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
⊢ 0 ≤ ∫ (a : Ω), ∑ c ∈ Finset.range (N + 1), {ω | τ ω ≤ c ∧ c < π ω}.indicator (f (c + 1) - f c) a ∂μ

tactic: have : ∀ i, MeasurableSet[𝒢 i] {ω : Ω | τ ω ≤ i ∧ i < π ω} := by
  intro i
  refine (hτ i).inter ?_
  convert (hπ i).compl using 1
  ext x
  simp; rfl
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
⊢ 0 ≤ ∫ (a : Ω), ∑ c ∈ Finset.range (N + 1), {ω | τ ω ≤ c ∧ c < π ω}.indicator (f (c + 1) - f c) a ∂μ
state_after: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
⊢ 0 ≤ ∫ (a : Ω), ∑ c ∈ Finset.range (N + 1), {ω | τ ω ≤ c ∧ c < π ω}.indicator (f (c + 1) - f c) a ∂μ

tactic: rw [integral_finset_sum]
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
⊢ 0 ≤ ∫ (a : Ω), ∑ c ∈ Finset.range (N + 1), {ω | τ ω ≤ c ∧ c < π ω}.indicator (f (c + 1) - f c) a ∂μ
state_after: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
⊢ 0 ≤ ∑ i ∈ Finset.range (N + 1), ∫ (a : Ω), {ω | τ ω ≤ i ∧ i < π ω}.indicator (f (i + 1) - f i) a ∂μ

case hf
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
⊢ ∀ i ∈ Finset.range (N + 1), Integrable ({ω | τ ω ≤ i ∧ i < π ω}.indicator (f (i + 1) - f i)) μ

tactic: intro i _
state_before: case hf
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
⊢ ∀ i ∈ Finset.range (N + 1), Integrable ({ω | τ ω ≤ i ∧ i < π ω}.indicator (f (i + 1) - f i)) μ
state_after: case hf
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
i : ℕ
a✝ : i ∈ Finset.range (N + 1)
⊢ Integrable ({ω | τ ω ≤ i ∧ i < π ω}.indicator (f (i + 1) - f i)) μ

tactic: exact Integrable.indicator (Integrable.sub (hf.integrable _) (hf.integrable _))
  (𝒢.le _ _ (this _))
state_before: case hf
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
i : ℕ
a✝ : i ∈ Finset.range (N + 1)
⊢ Integrable ({ω | τ ω ≤ i ∧ i < π ω}.indicator (f (i + 1) - f i)) μ
state_after: no goals

tactic: intro i
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
⊢ ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
state_after: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
i : ℕ
⊢ MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}

tactic: refine (hτ i).inter ?_
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
i : ℕ
⊢ MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
state_after: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
i : ℕ
⊢ MeasurableSet fun ω => i.succ.le (π ω)

tactic: convert (hπ i).compl using 1
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
i : ℕ
⊢ MeasurableSet fun ω => i.succ.le (π ω)
state_after: case h.e'_3
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
i : ℕ
⊢ (fun ω => i.succ.le (π ω)) = {ω | π ω ≤ i}ᶜ

tactic: ext x
state_before: case h.e'_3
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
i : ℕ
⊢ (fun ω => i.succ.le (π ω)) = {ω | π ω ≤ i}ᶜ
state_after: case h.e'_3.h
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
i : ℕ
x : Ω
⊢ (x ∈ fun ω => i.succ.le (π ω)) ↔ x ∈ {ω | π ω ≤ i}ᶜ

tactic: simp
state_before: case h.e'_3.h
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
i : ℕ
x : Ω
⊢ (x ∈ fun ω => i.succ.le (π ω)) ↔ x ∈ {ω | π ω ≤ i}ᶜ
state_after: case h.e'_3.h
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
i : ℕ
x : Ω
⊢ (x ∈ fun ω => i + 1 ≤ π ω) ↔ i < π x

tactic: rfl
state_before: case h.e'_3.h
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
i : ℕ
x : Ω
⊢ (x ∈ fun ω => i + 1 ≤ π ω) ↔ i < π x
state_after: no goals

tactic: refine Finset.sum_nonneg fun i _ => ?_
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
⊢ 0 ≤ ∑ i ∈ Finset.range (N + 1), ∫ (a : Ω), {ω | τ ω ≤ i ∧ i < π ω}.indicator (f (i + 1) - f i) a ∂μ
state_after: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
i : ℕ
x✝ : i ∈ Finset.range (N + 1)
⊢ 0 ≤ ∫ (a : Ω), {ω | τ ω ≤ i ∧ i < π ω}.indicator (f (i + 1) - f i) a ∂μ

tactic: rw [integral_indicator (𝒢.le _ _ (this _)), integral_sub', sub_nonneg]
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
i : ℕ
x✝ : i ∈ Finset.range (N + 1)
⊢ 0 ≤ ∫ (a : Ω), {ω | τ ω ≤ i ∧ i < π ω}.indicator (f (i + 1) - f i) a ∂μ
state_after: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
i : ℕ
x✝ : i ∈ Finset.range (N + 1)
⊢ ∫ (a : Ω) in {ω | τ ω ≤ i ∧ i < π ω}, f i a ∂μ ≤ ∫ (a : Ω) in {ω | τ ω ≤ i ∧ i < π ω}, f (i + 1) a ∂μ

case hf
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
i : ℕ
x✝ : i ∈ Finset.range (N + 1)
⊢ Integrable (f (i + 1)) (μ.restrict {ω | τ ω ≤ i ∧ i < π ω})

case hg
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
i : ℕ
x✝ : i ∈ Finset.range (N + 1)
⊢ Integrable (f i) (μ.restrict {ω | τ ω ≤ i ∧ i < π ω})

tactic: exact hf.setIntegral_le (Nat.le_succ i) (this _)
state_before: Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
i : ℕ
x✝ : i ∈ Finset.range (N + 1)
⊢ ∫ (a : Ω) in {ω | τ ω ≤ i ∧ i < π ω}, f i a ∂μ ≤ ∫ (a : Ω) in {ω | τ ω ≤ i ∧ i < π ω}, f (i + 1) a ∂μ
state_after: no goals

tactic: exact (hf.integrable _).integrableOn
state_before: case hf
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
i : ℕ
x✝ : i ∈ Finset.range (N + 1)
⊢ Integrable (f (i + 1)) (μ.restrict {ω | τ ω ≤ i ∧ i < π ω})
state_after: no goals

tactic: exact (hf.integrable _).integrableOn
state_before: case hg
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
this : ∀ (i : ℕ), MeasurableSet {ω | τ ω ≤ i ∧ i < π ω}
i : ℕ
x✝ : i ∈ Finset.range (N + 1)
⊢ Integrable (f i) (μ.restrict {ω | τ ω ≤ i ∧ i < π ω})
state_after: no goals

tactic: exact hf.integrable_stoppedValue hπ hbdd
state_before: case hf
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
⊢ Integrable (stoppedValue f π) μ
state_after: no goals

tactic: exact hf.integrable_stoppedValue hτ fun ω => le_trans (hle ω) (hbdd ω)
state_before: case hg
Ω : Type u_1
m0 : MeasurableSpace Ω
μ : Measure Ω
𝒢 : Filtration ℕ m0
f : ℕ → Ω → ℝ
τ π : Ω → ℕ
inst✝ : SigmaFiniteFiltration μ 𝒢
hf : Submartingale f 𝒢 μ
hτ : IsStoppingTime 𝒢 τ
hπ : IsStoppingTime 𝒢 π
hle : τ ≤ π
N : ℕ
hbdd : ∀ (ω : Ω), π ω ≤ N
⊢ Integrable (stoppedValue f τ) μ
state_after: no goals