Theorem: MeasureTheory.AEStronglyMeasurable.nullMeasurableSet_eq_fun
File: Mathlib/MeasureTheory/Function/StronglyMeasurable/Basic.lean

Proof steps:
state_before: α : Type u_1
β : Type u_2
γ : Type u_3
ι : Type u_4
inst✝⁴ : Countable ι
m : MeasurableSpace α
μ ν : Measure α
inst✝³ : TopologicalSpace β
inst✝² : TopologicalSpace γ
f✝ g✝ : α → β
E : Type u_5
inst✝¹ : TopologicalSpace E
inst✝ : MetrizableSpace E
f g : α → E
hf : AEStronglyMeasurable f μ
hg : AEStronglyMeasurable g μ
⊢ NullMeasurableSet {x | f x = g x} μ
state_after: α : Type u_1
β : Type u_2
γ : Type u_3
ι : Type u_4
inst✝⁴ : Countable ι
m : MeasurableSpace α
μ ν : Measure α
inst✝³ : TopologicalSpace β
inst✝² : TopologicalSpace γ
f✝ g✝ : α → β
E : Type u_5
inst✝¹ : TopologicalSpace E
inst✝ : MetrizableSpace E
f g : α → E
hf : AEStronglyMeasurable f μ
hg : AEStronglyMeasurable g μ
⊢ {x | AEStronglyMeasurable.mk f hf x = AEStronglyMeasurable.mk g hg x} =ᶠ[ae μ] {x | f x = g x}
tactic: apply
    (hf.stronglyMeasurable_mk.measurableSet_eq_fun
          hg.stronglyMeasurable_mk).nullMeasurableSet.congr
state_before: α : Type u_1
β : Type u_2
γ : Type u_3
ι : Type u_4
inst✝⁴ : Countable ι
m : MeasurableSpace α
μ ν : Measure α
inst✝³ : TopologicalSpace β
inst✝² : TopologicalSpace γ
f✝ g✝ : α → β
E : Type u_5
inst✝¹ : TopologicalSpace E
inst✝ : MetrizableSpace E
f g : α → E
hf : AEStronglyMeasurable f μ
hg : AEStronglyMeasurable g μ
⊢ {x | AEStronglyMeasurable.mk f hf x = AEStronglyMeasurable.mk g hg x} =ᶠ[ae μ] {x | f x = g x}
state_after: case h
α : Type u_1
β : Type u_2
γ : Type u_3
ι : Type u_4
inst✝⁴ : Countable ι
m : MeasurableSpace α
μ ν : Measure α
inst✝³ : TopologicalSpace β
inst✝² : TopologicalSpace γ
f✝ g✝ : α → β
E : Type u_5
inst✝¹ : TopologicalSpace E
inst✝ : MetrizableSpace E
f g : α → E
hf : AEStronglyMeasurable f μ
hg : AEStronglyMeasurable g μ
x : α
hfx : f x = AEStronglyMeasurable.mk f hf x
hgx : g x = AEStronglyMeasurable.mk g hg x
⊢ {x | AEStronglyMeasurable.mk f hf x = AEStronglyMeasurable.mk g hg x} x = {x | f x = g x} x
tactic: filter_upwards [hf.ae_eq_mk, hg.ae_eq_mk] with x hfx hgx
state_before: case h
α : Type u_1
β : Type u_2
γ : Type u_3
ι : Type u_4
inst✝⁴ : Countable ι
m : MeasurableSpace α
μ ν : Measure α
inst✝³ : TopologicalSpace β
inst✝² : TopologicalSpace γ
f✝ g✝ : α → β
E : Type u_5
inst✝¹ : TopologicalSpace E
inst✝ : MetrizableSpace E
f g : α → E
hf : AEStronglyMeasurable f μ
hg : AEStronglyMeasurable g μ
x : α
hfx : f x = AEStronglyMeasurable.mk f hf x
hgx : g x = AEStronglyMeasurable.mk g hg x
⊢ {x | AEStronglyMeasurable.mk f hf x = AEStronglyMeasurable.mk g hg x} x = {x | f x = g x} x
state_after: case h
α : Type u_1
β : Type u_2
γ : Type u_3
ι : Type u_4
inst✝⁴ : Countable ι
m : MeasurableSpace α
μ ν : Measure α
inst✝³ : TopologicalSpace β
inst✝² : TopologicalSpace γ
f✝ g✝ : α → β
E : Type u_5
inst✝¹ : TopologicalSpace E
inst✝ : MetrizableSpace E
f g : α → E
hf : AEStronglyMeasurable f μ
hg : AEStronglyMeasurable g μ
x : α
hfx : f x = AEStronglyMeasurable.mk f hf x
hgx : g x = AEStronglyMeasurable.mk g hg x
⊢ (AEStronglyMeasurable.mk f hf x = AEStronglyMeasurable.mk g hg x) = (f x = g x)
tactic: change (hf.mk f x = hg.mk g x) = (f x = g x)
state_before: case h
α : Type u_1
β : Type u_2
γ : Type u_3
ι : Type u_4
inst✝⁴ : Countable ι
m : MeasurableSpace α
μ ν : Measure α
inst✝³ : TopologicalSpace β
inst✝² : TopologicalSpace γ
f✝ g✝ : α → β
E : Type u_5
inst✝¹ : TopologicalSpace E
inst✝ : MetrizableSpace E
f g : α → E
hf : AEStronglyMeasurable f μ
hg : AEStronglyMeasurable g μ
x : α
hfx : f x = AEStronglyMeasurable.mk f hf x
hgx : g x = AEStronglyMeasurable.mk g hg x
⊢ (AEStronglyMeasurable.mk f hf x = AEStronglyMeasurable.mk g hg x) = (f x = g x)
state_after: no goals
tactic: simp only [hfx, hgx]