Module: Mathlib.MeasureTheory.Measure.Decomposition.IntegralRNDeriv

Goal state before:
pp: 𝓧 : Type u_1
m𝓧 : MeasurableSpace 𝓧
μ ν : Measure 𝓧
f : ℝ → ℝ
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
hf_cvx : ConvexOn ℝ (Ici 0) f
hf_cont : ContinuousWithinAt f (Ici 0) 0
hf_int : Integrable (fun x ↦ f (μ.rnDeriv ν x).toReal) ν
hμν : μ ≪ ν
hν : ¬ν = 0
this✝ : NeZero ν
μ' : Measure 𝓧 := (ν univ)⁻¹ • μ
ν' : Measure 𝓧 := (ν univ)⁻¹ • ν
this : IsFiniteMeasure μ'
hμν' : μ' ≪ ν'
h1' : μ'.rnDeriv ν' =ᵐ[ν'] (ν univ)⁻¹ • μ.rnDeriv ν'
h1✝ : μ'.rnDeriv ν' =ᵐ[ν] (ν univ)⁻¹ • μ.rnDeriv ν'
h2✝ : μ.rnDeriv ν' =ᵐ[ν] (ν univ)⁻¹⁻¹ • μ.rnDeriv ν
x : 𝓧
h1 : μ'.rnDeriv ν' x = ((ν univ)⁻¹ • μ.rnDeriv ν') x
h2 : μ.rnDeriv ν' x = ((ν univ)⁻¹⁻¹ • μ.rnDeriv ν) x
⊢ μ.rnDeriv ν x = μ.rnDeriv ν x

pp: case h0
𝓧 : Type u_1
m𝓧 : MeasurableSpace 𝓧
μ ν : Measure 𝓧
f : ℝ → ℝ
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
hf_cvx : ConvexOn ℝ (Ici 0) f
hf_cont : ContinuousWithinAt f (Ici 0) 0
hf_int : Integrable (fun x ↦ f (μ.rnDeriv ν x).toReal) ν
hμν : μ ≪ ν
hν : ¬ν = 0
this✝ : NeZero ν
μ' : Measure 𝓧 := (ν univ)⁻¹ • μ
ν' : Measure 𝓧 := (ν univ)⁻¹ • ν
this : IsFiniteMeasure μ'
hμν' : μ' ≪ ν'
h1' : μ'.rnDeriv ν' =ᵐ[ν'] (ν univ)⁻¹ • μ.rnDeriv ν'
h1✝ : μ'.rnDeriv ν' =ᵐ[ν] (ν univ)⁻¹ • μ.rnDeriv ν'
h2✝ : μ.rnDeriv ν' =ᵐ[ν] (ν univ)⁻¹⁻¹ • μ.rnDeriv ν
x : 𝓧
h1 : μ'.rnDeriv ν' x = ((ν univ)⁻¹ • μ.rnDeriv ν') x
h2 : μ.rnDeriv ν' x = ((ν univ)⁻¹⁻¹ • μ.rnDeriv ν) x
⊢ ν univ ≠ 0

pp: case ht
𝓧 : Type u_1
m𝓧 : MeasurableSpace 𝓧
μ ν : Measure 𝓧
f : ℝ → ℝ
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
hf_cvx : ConvexOn ℝ (Ici 0) f
hf_cont : ContinuousWithinAt f (Ici 0) 0
hf_int : Integrable (fun x ↦ f (μ.rnDeriv ν x).toReal) ν
hμν : μ ≪ ν
hν : ¬ν = 0
this✝ : NeZero ν
μ' : Measure 𝓧 := (ν univ)⁻¹ • μ
ν' : Measure 𝓧 := (ν univ)⁻¹ • ν
this : IsFiniteMeasure μ'
hμν' : μ' ≪ ν'
h1' : μ'.rnDeriv ν' =ᵐ[ν'] (ν univ)⁻¹ • μ.rnDeriv ν'
h1✝ : μ'.rnDeriv ν' =ᵐ[ν] (ν univ)⁻¹ • μ.rnDeriv ν'
h2✝ : μ.rnDeriv ν' =ᵐ[ν] (ν univ)⁻¹⁻¹ • μ.rnDeriv ν
x : 𝓧
h1 : μ'.rnDeriv ν' x = ((ν univ)⁻¹ • μ.rnDeriv ν') x
h2 : μ.rnDeriv ν' x = ((ν univ)⁻¹⁻¹ • μ.rnDeriv ν) x
⊢ ν univ ≠ ∞

Tactic:
]

Goal state after:
case h0
𝓧 : Type u_1
m𝓧 : MeasurableSpace 𝓧
μ ν : Measure 𝓧
f : ℝ → ℝ
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
hf_cvx : ConvexOn ℝ (Ici 0) f
hf_cont : ContinuousWithinAt f (Ici 0) 0
hf_int : Integrable (fun x ↦ f (μ.rnDeriv ν x).toReal) ν
hμν : μ ≪ ν
hν : ¬ν = 0
this✝ : NeZero ν
μ' : Measure 𝓧 := (ν univ)⁻¹ • μ
ν' : Measure 𝓧 := (ν univ)⁻¹ • ν
this : IsFiniteMeasure μ'
hμν' : μ' ≪ ν'
h1' : μ'.rnDeriv ν' =ᵐ[ν'] (ν univ)⁻¹ • μ.rnDeriv ν'
h1✝ : μ'.rnDeriv ν' =ᵐ[ν] (ν univ)⁻¹ • μ.rnDeriv ν'
h2✝ : μ.rnDeriv ν' =ᵐ[ν] (ν univ)⁻¹⁻¹ • μ.rnDeriv ν
x : 𝓧
h1 : μ'.rnDeriv ν' x = ((ν univ)⁻¹ • μ.rnDeriv ν') x
h2 : μ.rnDeriv ν' x = ((ν univ)⁻¹⁻¹ • μ.rnDeriv ν) x
⊢ ν univ ≠ 0

case ht
𝓧 : Type u_1
m𝓧 : MeasurableSpace 𝓧
μ ν : Measure 𝓧
f : ℝ → ℝ
inst✝¹ : IsFiniteMeasure μ
inst✝ : IsFiniteMeasure ν
hf_cvx : ConvexOn ℝ (Ici 0) f
hf_cont : ContinuousWithinAt f (Ici 0) 0
hf_int : Integrable (fun x ↦ f (μ.rnDeriv ν x).toReal) ν
hμν : μ ≪ ν
hν : ¬ν = 0
this✝ : NeZero ν
μ' : Measure 𝓧 := (ν univ)⁻¹ • μ
ν' : Measure 𝓧 := (ν univ)⁻¹ • ν
this : IsFiniteMeasure μ'
hμν' : μ' ≪ ν'
h1' : μ'.rnDeriv ν' =ᵐ[ν'] (ν univ)⁻¹ • μ.rnDeriv ν'
h1✝ : μ'.rnDeriv ν' =ᵐ[ν] (ν univ)⁻¹ • μ.rnDeriv ν'
h2✝ : μ.rnDeriv ν' =ᵐ[ν] (ν univ)⁻¹⁻¹ • μ.rnDeriv ν
x : 𝓧
h1 : μ'.rnDeriv ν' x = ((ν univ)⁻¹ • μ.rnDeriv ν') x
h2 : μ.rnDeriv ν' x = ((ν univ)⁻¹⁻¹ • μ.rnDeriv ν) x
⊢ ν univ ≠ ∞