Theorem: MeasureTheory.ae_map_mem_range
File: Mathlib/MeasureTheory/Measure/MeasureSpace.lean

tactic: by_cases h : AEMeasurable f μ
state_before: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0✝ : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
m0 : MeasurableSpace α
f : α → β
hf : MeasurableSet (range f)
μ : Measure α
⊢ ∀ᵐ (x : β) ∂Measure.map f μ, x ∈ range f
state_after: case pos
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0✝ : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
m0 : MeasurableSpace α
f : α → β
hf : MeasurableSet (range f)
μ : Measure α
h : AEMeasurable f μ
⊢ ∀ᵐ (x : β) ∂Measure.map f μ, x ∈ range f

case neg
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0✝ : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
m0 : MeasurableSpace α
f : α → β
hf : MeasurableSet (range f)
μ : Measure α
h : ¬AEMeasurable f μ
⊢ ∀ᵐ (x : β) ∂Measure.map f μ, x ∈ range f

tactic: change range f ∈ ae (μ.map f)
state_before: case pos
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0✝ : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
m0 : MeasurableSpace α
f : α → β
hf : MeasurableSet (range f)
μ : Measure α
h : AEMeasurable f μ
⊢ ∀ᵐ (x : β) ∂Measure.map f μ, x ∈ range f
state_after: case pos
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0✝ : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
m0 : MeasurableSpace α
f : α → β
hf : MeasurableSet (range f)
μ : Measure α
h : AEMeasurable f μ
⊢ range f ∈ ae (Measure.map f μ)

tactic: rw [mem_ae_map_iff h hf]
state_before: case pos
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0✝ : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
m0 : MeasurableSpace α
f : α → β
hf : MeasurableSet (range f)
μ : Measure α
h : AEMeasurable f μ
⊢ range f ∈ ae (Measure.map f μ)
state_after: case pos
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0✝ : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
m0 : MeasurableSpace α
f : α → β
hf : MeasurableSet (range f)
μ : Measure α
h : AEMeasurable f μ
⊢ f ⁻¹' range f ∈ ae μ

tactic: filter_upwards using mem_range_self
state_before: case pos
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0✝ : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
m0 : MeasurableSpace α
f : α → β
hf : MeasurableSet (range f)
μ : Measure α
h : AEMeasurable f μ
⊢ f ⁻¹' range f ∈ ae μ
state_after: no goals

tactic: simp [map_of_not_aemeasurable h]
state_before: case neg
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0✝ : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
m0 : MeasurableSpace α
f : α → β
hf : MeasurableSet (range f)
μ : Measure α
h : ¬AEMeasurable f μ
⊢ ∀ᵐ (x : β) ∂Measure.map f μ, x ∈ range f
state_after: no goals