@@ -5,7 +5,7 @@ Authors: Louis (Yiyang) Liu
55-/
66module
77
8- public import Mathlib.MeasureTheory.Integral.Average.MeanValue
8+ public import Mathlib.MeasureTheory.Integral.Average
99
1010/-!
1111# First mean value theorem for set integrals
@@ -36,11 +36,8 @@ Let `s` be a connected measurable set. If `f` is continuous on `s`, `g` is integ
3636`f * g` is integrable on `s`, and `g` is nonnegative a.e. on `s` w.r.t. `μ.restrict s`, then
3737`∃ c ∈ s, (∫ x in s, f x * g x ∂μ) = f c * (∫ x in s, g x ∂μ)`. -/
3838theorem exists_eq_const_mul_setIntegral_of_ae_nonneg
39- (hs_conn : IsConnected s)
40- (hs_meas : MeasurableSet s)
41- (hf : ContinuousOn f s)
42- (hg : IntegrableOn g s μ)
43- (hfg : IntegrableOn (fun x ↦ f x * g x) s μ)
39+ (hs_conn : IsConnected s) (hs_meas : MeasurableSet s) (hf : ContinuousOn f s)
40+ (hg : IntegrableOn g s μ) (hfg : IntegrableOn (fun x ↦ f x * g x) s μ)
4441 (hg0 : ∀ᵐ x ∂(μ.restrict s), 0 ≤ g x) :
4542 ∃ c ∈ s, (∫ x in s, f x * g x ∂μ) = f c * (∫ x in s, g x ∂μ) := by
4643 let ρ := fun x ↦ ENNReal.ofReal (g x)
@@ -96,7 +93,7 @@ theorem exists_eq_const_mul_setIntegral_of_ae_nonneg
9693 rw [integrableOn_congr_fun_ae hmul_ae]
9794 exact hfg
9895 have h_Int : Integrable f ((μ.restrict s).withDensity ρ) := by
99- rwa [integrable_withDensity_iff_integrable_smul₀' hρ_ae hρ_top, ←IntegrableOn]
96+ rwa [integrable_withDensity_iff_integrable_smul₀' hρ_ae hρ_top, ← IntegrableOn]
10097 have hνrs : ν.restrict s = (μ.restrict s).withDensity ρ := by
10198 ext t ht
10299 have hts : MeasurableSet (t ∩ s) := ht.inter hs_meas
@@ -119,11 +116,8 @@ Let `s` be a connected measurable set. If `f` is continuous on `s`, `g` is integ
119116`f * g` is integrable on `s`, and `g` is nonnegative on `s`, then
120117`∃ c ∈ s, (∫ x in s, f x * g x ∂μ) = f c * (∫ x in s, g x ∂μ)` -/
121118theorem exists_eq_const_mul_setIntegral_of_nonneg
122- (hs_conn : IsConnected s)
123- (hs_meas : MeasurableSet s)
124- (hf : ContinuousOn f s)
125- (hg : IntegrableOn g s μ)
126- (hfg : IntegrableOn (fun x ↦ f x * g x) s μ)
119+ (hs_conn : IsConnected s) (hs_meas : MeasurableSet s) (hf : ContinuousOn f s)
120+ (hg : IntegrableOn g s μ) (hfg : IntegrableOn (fun x ↦ f x * g x) s μ)
127121 (hg0 : ∀ x ∈ s, 0 ≤ g x) :
128122 ∃ c ∈ s, (∫ x in s, f x * g x ∂μ) = f c * (∫ x in s, g x ∂μ) := by
129123 have hg0_ae : ∀ᵐ x ∂(μ.restrict s), 0 ≤ g x := by
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