Theorem: Monotone.locallyIntegrable
File: Mathlib/MeasureTheory/Function/LocallyIntegrable.lean

tactic: intro x
state_before: X : Type u_1
Y : Type ?u.2236679
E : Type u_2
R : Type ?u.2236685
inst✝¹¹ : MeasurableSpace X
inst✝¹⁰ : TopologicalSpace X
inst✝⁹ : MeasurableSpace Y
inst✝⁸ : TopologicalSpace Y
inst✝⁷ : NormedAddCommGroup E
f : X → E
μ : MeasureTheory.Measure X
s : Set X
inst✝⁶ : BorelSpace X
inst✝⁵ : ConditionallyCompleteLinearOrder X
inst✝⁴ : ConditionallyCompleteLinearOrder E
inst✝³ : OrderTopology X
inst✝² : OrderTopology E
inst✝¹ : SecondCountableTopology E
inst✝ : IsLocallyFiniteMeasure μ
hmono : Monotone f
⊢ LocallyIntegrable f

tactic: rcases μ.finiteAt_nhds x with ⟨U, hU, h'U⟩
state_before: X : Type u_1
Y : Type ?u.2236679
E : Type u_2
R : Type ?u.2236685
inst✝¹¹ : MeasurableSpace X
inst✝¹⁰ : TopologicalSpace X
inst✝⁹ : MeasurableSpace Y
inst✝⁸ : TopologicalSpace Y
inst✝⁷ : NormedAddCommGroup E
f : X → E
μ : MeasureTheory.Measure X
s : Set X
inst✝⁶ : BorelSpace X
inst✝⁵ : ConditionallyCompleteLinearOrder X
inst✝⁴ : ConditionallyCompleteLinearOrder E
inst✝³ : OrderTopology X
inst✝² : OrderTopology E
inst✝¹ : SecondCountableTopology E
inst✝ : IsLocallyFiniteMeasure μ
hmono : Monotone f
x : X
⊢ IntegrableAtFilter f (𝓝 x)

tactic: obtain ⟨a, b, xab, hab, abU⟩ : ∃ a b : X, x ∈ Icc a b ∧ Icc a b ∈ 𝓝 x ∧ Icc a b ⊆ U
state_before: case intro.intro
X : Type u_1
Y : Type ?u.2236679
E : Type u_2
R : Type ?u.2236685
inst✝¹¹ : MeasurableSpace X
inst✝¹⁰ : TopologicalSpace X
inst✝⁹ : MeasurableSpace Y
inst✝⁸ : TopologicalSpace Y
inst✝⁷ : NormedAddCommGroup E
f : X → E
μ : MeasureTheory.Measure X
s : Set X
inst✝⁶ : BorelSpace X
inst✝⁵ : ConditionallyCompleteLinearOrder X
inst✝⁴ : ConditionallyCompleteLinearOrder E
inst✝³ : OrderTopology X
inst✝² : OrderTopology E
inst✝¹ : SecondCountableTopology E
inst✝ : IsLocallyFiniteMeasure μ
hmono : Monotone f
x : X
U : Set X
hU : U ∈ 𝓝 x
h'U : ↑↑μ U < ⊤
⊢ IntegrableAtFilter f (𝓝 x)

tactic: exact exists_Icc_mem_subset_of_mem_nhds hU
state_before: X : Type u_1
Y : Type ?u.2236679
E : Type u_2
R : Type ?u.2236685
inst✝¹¹ : MeasurableSpace X
inst✝¹⁰ : TopologicalSpace X
inst✝⁹ : MeasurableSpace Y
inst✝⁸ : TopologicalSpace Y
inst✝⁷ : NormedAddCommGroup E
f : X → E
μ : MeasureTheory.Measure X
s : Set X
inst✝⁶ : BorelSpace X
inst✝⁵ : ConditionallyCompleteLinearOrder X
inst✝⁴ : ConditionallyCompleteLinearOrder E
inst✝³ : OrderTopology X
inst✝² : OrderTopology E
inst✝¹ : SecondCountableTopology E
inst✝ : IsLocallyFiniteMeasure μ
hmono : Monotone f
x : X
U : Set X
hU : U ∈ 𝓝 x
h'U : ↑↑μ U < ⊤
⊢ ∃ a b, x ∈ Icc a b ∧ Icc a b ∈ 𝓝 x ∧ Icc a b ⊆ U

case intro.intro.intro.intro.intro.intro
X : Type u_1
Y : Type ?u.2236679
E : Type u_2
R : Type ?u.2236685
inst✝¹¹ : MeasurableSpace X
inst✝¹⁰ : TopologicalSpace X
inst✝⁹ : MeasurableSpace Y
inst✝⁸ : TopologicalSpace Y
inst✝⁷ : NormedAddCommGroup E
f : X → E
μ : MeasureTheory.Measure X
s : Set X
inst✝⁶ : BorelSpace X
inst✝⁵ : ConditionallyCompleteLinearOrder X
inst✝⁴ : ConditionallyCompleteLinearOrder E
inst✝³ : OrderTopology X
inst✝² : OrderTopology E
inst✝¹ : SecondCountableTopology E
inst✝ : IsLocallyFiniteMeasure μ
hmono : Monotone f
x : X
U : Set X
hU : U ∈ 𝓝 x
h'U : ↑↑μ U < ⊤
a b : X
xab : x ∈ Icc a b
hab : Icc a b ∈ 𝓝 x
abU : Icc a b ⊆ U
⊢ IntegrableAtFilter f (𝓝 x)

tactic: have ab : a ≤ b := xab.1.trans xab.2
state_before: case intro.intro.intro.intro.intro.intro
X : Type u_1
Y : Type ?u.2236679
E : Type u_2
R : Type ?u.2236685
inst✝¹¹ : MeasurableSpace X
inst✝¹⁰ : TopologicalSpace X
inst✝⁹ : MeasurableSpace Y
inst✝⁸ : TopologicalSpace Y
inst✝⁷ : NormedAddCommGroup E
f : X → E
μ : MeasureTheory.Measure X
s : Set X
inst✝⁶ : BorelSpace X
inst✝⁵ : ConditionallyCompleteLinearOrder X
inst✝⁴ : ConditionallyCompleteLinearOrder E
inst✝³ : OrderTopology X
inst✝² : OrderTopology E
inst✝¹ : SecondCountableTopology E
inst✝ : IsLocallyFiniteMeasure μ
hmono : Monotone f
x : X
U : Set X
hU : U ∈ 𝓝 x
h'U : ↑↑μ U < ⊤
a b : X
xab : x ∈ Icc a b
hab : Icc a b ∈ 𝓝 x
abU : Icc a b ⊆ U
⊢ IntegrableAtFilter f (𝓝 x)

tactic: refine' ⟨Icc a b, hab, _⟩
state_before: case intro.intro.intro.intro.intro.intro
X : Type u_1
Y : Type ?u.2236679
E : Type u_2
R : Type ?u.2236685
inst✝¹¹ : MeasurableSpace X
inst✝¹⁰ : TopologicalSpace X
inst✝⁹ : MeasurableSpace Y
inst✝⁸ : TopologicalSpace Y
inst✝⁷ : NormedAddCommGroup E
f : X → E
μ : MeasureTheory.Measure X
s : Set X
inst✝⁶ : BorelSpace X
inst✝⁵ : ConditionallyCompleteLinearOrder X
inst✝⁴ : ConditionallyCompleteLinearOrder E
inst✝³ : OrderTopology X
inst✝² : OrderTopology E
inst✝¹ : SecondCountableTopology E
inst✝ : IsLocallyFiniteMeasure μ
hmono : Monotone f
x : X
U : Set X
hU : U ∈ 𝓝 x
h'U : ↑↑μ U < ⊤
a b : X
xab : x ∈ Icc a b
hab : Icc a b ∈ 𝓝 x
abU : Icc a b ⊆ U
ab : a ≤ b
⊢ IntegrableAtFilter f (𝓝 x)

tactic: exact
  (hmono.monotoneOn _).integrableOn_of_measure_ne_top (isLeast_Icc ab) (isGreatest_Icc ab)
    ((measure_mono abU).trans_lt h'U).ne measurableSet_Icc
state_before: case intro.intro.intro.intro.intro.intro
X : Type u_1
Y : Type ?u.2236679
E : Type u_2
R : Type ?u.2236685
inst✝¹¹ : MeasurableSpace X
inst✝¹⁰ : TopologicalSpace X
inst✝⁹ : MeasurableSpace Y
inst✝⁸ : TopologicalSpace Y
inst✝⁷ : NormedAddCommGroup E
f : X → E
μ : MeasureTheory.Measure X
s : Set X
inst✝⁶ : BorelSpace X
inst✝⁵ : ConditionallyCompleteLinearOrder X
inst✝⁴ : ConditionallyCompleteLinearOrder E
inst✝³ : OrderTopology X
inst✝² : OrderTopology E
inst✝¹ : SecondCountableTopology E
inst✝ : IsLocallyFiniteMeasure μ
hmono : Monotone f
x : X
U : Set X
hU : U ∈ 𝓝 x
h'U : ↑↑μ U < ⊤
a b : X
xab : x ∈ Icc a b
hab : Icc a b ∈ 𝓝 x
abU : Icc a b ⊆ U
ab : a ≤ b
⊢ IntegrableOn f (Icc a b)