Documentation

Mathlib.MeasureTheory.Function.L1Space.Integrable

Integrable functions #

In this file, the predicate Integrable is defined and basic properties of integrable functions are proved.

Such a predicate is already available under the name Memℒp 1. We give a direct definition which is easier to use, and show that it is equivalent to Memℒp 1.

Main definition #

Implementation notes #

To prove something for an arbitrary integrable function, a useful theorem is Integrable.induction in the file SetIntegral.

Tags #

integrable

The predicate Integrable #

def MeasureTheory.Integrable {ε : Type u_5} [ENorm ε] [TopologicalSpace ε] {α : Type u_6} {x✝ : MeasurableSpace α} (f : αε) (μ : Measure α := by volume_tac) :

Integrable f μ means that f is measurable and that the integral ∫⁻ a, ‖f a‖ ∂μ is finite. Integrable f means Integrable f volume.

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    Notation for Integrable with respect to a non-standard σ-algebra.

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    • One or more equations did not get rendered due to their size.
    Instances For
      theorem MeasureTheory.memℒp_one_iff_integrable {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} :
      Memℒp f 1 μ Integrable f μ
      theorem MeasureTheory.Integrable.aestronglyMeasurable {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} (hf : Integrable f μ) :
      theorem MeasureTheory.Integrable.aemeasurable {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [MeasurableSpace β] [BorelSpace β] {f : αβ} (hf : Integrable f μ) :
      theorem MeasureTheory.Integrable.hasFiniteIntegral {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} (hf : Integrable f μ) :
      theorem MeasureTheory.Integrable.mono {α : Type u_1} {β : Type u_2} {γ : Type u_3} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [NormedAddCommGroup γ] {f : αβ} {g : αγ} (hg : Integrable g μ) (hf : AEStronglyMeasurable f μ) (h : ∀ᵐ (a : α) μ, f a g a) :
      theorem MeasureTheory.Integrable.mono' {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} {g : α} (hg : Integrable g μ) (hf : AEStronglyMeasurable f μ) (h : ∀ᵐ (a : α) μ, f a g a) :
      theorem MeasureTheory.Integrable.congr' {α : Type u_1} {β : Type u_2} {γ : Type u_3} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [NormedAddCommGroup γ] {f : αβ} {g : αγ} (hf : Integrable f μ) (hg : AEStronglyMeasurable g μ) (h : ∀ᵐ (a : α) μ, f a = g a) :
      theorem MeasureTheory.integrable_congr' {α : Type u_1} {β : Type u_2} {γ : Type u_3} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [NormedAddCommGroup γ] {f : αβ} {g : αγ} (hf : AEStronglyMeasurable f μ) (hg : AEStronglyMeasurable g μ) (h : ∀ᵐ (a : α) μ, f a = g a) :
      theorem MeasureTheory.Integrable.congr {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f g : αβ} (hf : Integrable f μ) (h : f =ᶠ[ae μ] g) :
      theorem MeasureTheory.integrable_congr {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f g : αβ} (h : f =ᶠ[ae μ] g) :
      theorem MeasureTheory.integrable_const_iff {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {c : β} :
      Integrable (fun (x : α) => c) μ c = 0 IsFiniteMeasure μ
      theorem MeasureTheory.integrable_const_iff_isFiniteMeasure {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {c : β} (hc : c 0) :
      Integrable (fun (x : α) => c) μ IsFiniteMeasure μ
      theorem MeasureTheory.Integrable.of_mem_Icc {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} [IsFiniteMeasure μ] (a b : ) {X : α} (hX : AEMeasurable X μ) (h : ∀ᵐ (ω : α) μ, X ω Set.Icc a b) :
      @[simp]
      theorem MeasureTheory.integrable_const {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [IsFiniteMeasure μ] (c : β) :
      Integrable (fun (x : α) => c) μ
      @[simp]
      theorem MeasureTheory.Integrable.of_finite {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [Finite α] [MeasurableSingletonClass α] [IsFiniteMeasure μ] {f : αβ} :
      @[deprecated MeasureTheory.Integrable.of_finite (since := "2024-10-05")]
      theorem MeasureTheory.Integrable.of_isEmpty {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [IsEmpty α] {f : αβ} :

      This lemma is a special case of Integrable.of_finite.

      theorem MeasureTheory.Memℒp.integrable_norm_rpow {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} {p : ENNReal} (hf : Memℒp f p μ) (hp_ne_zero : p 0) (hp_ne_top : p ) :
      Integrable (fun (x : α) => f x ^ p.toReal) μ
      theorem MeasureTheory.Memℒp.integrable_norm_rpow' {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [IsFiniteMeasure μ] {f : αβ} {p : ENNReal} (hf : Memℒp f p μ) :
      Integrable (fun (x : α) => f x ^ p.toReal) μ
      theorem MeasureTheory.Memℒp.integrable_norm_pow {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} {p : } (hf : Memℒp f (↑p) μ) (hp : p 0) :
      Integrable (fun (x : α) => f x ^ p) μ
      theorem MeasureTheory.Memℒp.integrable_norm_pow' {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [IsFiniteMeasure μ] {f : αβ} {p : } (hf : Memℒp f (↑p) μ) :
      Integrable (fun (x : α) => f x ^ p) μ
      theorem MeasureTheory.integrable_norm_rpow_iff {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} {p : ENNReal} (hf : AEStronglyMeasurable f μ) (p_zero : p 0) (p_top : p ) :
      Integrable (fun (x : α) => f x ^ p.toReal) μ Memℒp f p μ
      theorem MeasureTheory.Integrable.mono_measure {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ ν : Measure α} [NormedAddCommGroup β] {f : αβ} (h : Integrable f ν) (hμ : μ ν) :
      theorem MeasureTheory.Integrable.of_measure_le_smul {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {μ' : Measure α} (c : ENNReal) (hc : c ) (hμ'_le : μ' c μ) {f : αβ} (hf : Integrable f μ) :
      theorem MeasureTheory.Integrable.add_measure {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ ν : Measure α} [NormedAddCommGroup β] {f : αβ} (hμ : Integrable f μ) (hν : Integrable f ν) :
      Integrable f (μ + ν)
      theorem MeasureTheory.Integrable.left_of_add_measure {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ ν : Measure α} [NormedAddCommGroup β] {f : αβ} (h : Integrable f (μ + ν)) :
      theorem MeasureTheory.Integrable.right_of_add_measure {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ ν : Measure α} [NormedAddCommGroup β] {f : αβ} (h : Integrable f (μ + ν)) :
      @[simp]
      theorem MeasureTheory.integrable_add_measure {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ ν : Measure α} [NormedAddCommGroup β] {f : αβ} :
      Integrable f (μ + ν) Integrable f μ Integrable f ν
      @[simp]
      theorem MeasureTheory.integrable_zero_measure {α : Type u_1} {β : Type u_2} [NormedAddCommGroup β] {x✝ : MeasurableSpace α} {f : αβ} :
      theorem MeasureTheory.integrable_finset_sum_measure {α : Type u_1} {β : Type u_2} [NormedAddCommGroup β] {ι : Type u_6} {m : MeasurableSpace α} {f : αβ} {μ : ιMeasure α} {s : Finset ι} :
      Integrable f (∑ is, μ i) is, Integrable f (μ i)
      theorem MeasureTheory.Integrable.smul_measure {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} (h : Integrable f μ) {c : ENNReal} (hc : c ) :
      Integrable f (c μ)
      theorem MeasureTheory.Integrable.smul_measure_nnreal {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} (h : Integrable f μ) {c : NNReal} :
      Integrable f (c μ)
      theorem MeasureTheory.integrable_smul_measure {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} {c : ENNReal} (h₁ : c 0) (h₂ : c ) :
      theorem MeasureTheory.integrable_inv_smul_measure {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} {c : ENNReal} (h₁ : c 0) (h₂ : c ) :
      theorem MeasureTheory.Integrable.to_average {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} (h : Integrable f μ) :
      theorem MeasureTheory.integrable_average {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [IsFiniteMeasure μ] {f : αβ} :
      theorem MeasureTheory.integrable_map_measure {α : Type u_1} {β : Type u_2} {δ : Type u_4} {m : MeasurableSpace α} {μ : Measure α} [MeasurableSpace δ] [NormedAddCommGroup β] {f : αδ} {g : δβ} (hg : AEStronglyMeasurable g (Measure.map f μ)) (hf : AEMeasurable f μ) :
      theorem MeasureTheory.Integrable.comp_aemeasurable {α : Type u_1} {β : Type u_2} {δ : Type u_4} {m : MeasurableSpace α} {μ : Measure α} [MeasurableSpace δ] [NormedAddCommGroup β] {f : αδ} {g : δβ} (hg : Integrable g (Measure.map f μ)) (hf : AEMeasurable f μ) :
      Integrable (g f) μ
      theorem MeasureTheory.Integrable.comp_measurable {α : Type u_1} {β : Type u_2} {δ : Type u_4} {m : MeasurableSpace α} {μ : Measure α} [MeasurableSpace δ] [NormedAddCommGroup β] {f : αδ} {g : δβ} (hg : Integrable g (Measure.map f μ)) (hf : Measurable f) :
      Integrable (g f) μ
      theorem MeasureTheory.integrable_map_equiv {α : Type u_1} {β : Type u_2} {δ : Type u_4} {m : MeasurableSpace α} {μ : Measure α} [MeasurableSpace δ] [NormedAddCommGroup β] (f : α ≃ᵐ δ) (g : δβ) :
      Integrable g (Measure.map (⇑f) μ) Integrable (g f) μ
      theorem MeasureTheory.MeasurePreserving.integrable_comp {α : Type u_1} {β : Type u_2} {δ : Type u_4} {m : MeasurableSpace α} {μ : Measure α} [MeasurableSpace δ] [NormedAddCommGroup β] {ν : Measure δ} {g : δβ} {f : αδ} (hf : MeasurePreserving f μ ν) (hg : AEStronglyMeasurable g ν) :
      theorem MeasureTheory.MeasurePreserving.integrable_comp_emb {α : Type u_1} {β : Type u_2} {δ : Type u_4} {m : MeasurableSpace α} {μ : Measure α} [MeasurableSpace δ] [NormedAddCommGroup β] {f : αδ} {ν : Measure δ} (h₁ : MeasurePreserving f μ ν) (h₂ : MeasurableEmbedding f) {g : δβ} :
      theorem MeasureTheory.lintegral_edist_lt_top {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f g : αβ} (hf : Integrable f μ) (hg : Integrable g μ) :
      ∫⁻ (a : α), edist (f a) (g a) μ <
      @[simp]
      theorem MeasureTheory.integrable_zero (α : Type u_1) (β : Type u_2) {m : MeasurableSpace α} (μ : Measure α) [NormedAddCommGroup β] :
      Integrable (fun (x : α) => 0) μ
      theorem MeasureTheory.Integrable.add' {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f g : αβ} (hf : Integrable f μ) (hg : Integrable g μ) :
      theorem MeasureTheory.Integrable.add {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f g : αβ} (hf : Integrable f μ) (hg : Integrable g μ) :
      Integrable (f + g) μ
      theorem MeasureTheory.Integrable.add'' {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f g : αβ} (hf : Integrable f μ) (hg : Integrable g μ) :
      Integrable (fun (x : α) => f x + g x) μ
      theorem MeasureTheory.integrable_finset_sum' {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {ι : Type u_6} (s : Finset ι) {f : ιαβ} (hf : is, Integrable (f i) μ) :
      Integrable (∑ is, f i) μ
      theorem MeasureTheory.integrable_finset_sum {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {ι : Type u_6} (s : Finset ι) {f : ιαβ} (hf : is, Integrable (f i) μ) :
      Integrable (fun (a : α) => is, f i a) μ
      theorem MeasureTheory.Integrable.neg {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} (hf : Integrable f μ) :

      If f is integrable, then so is -f. See Integrable.neg' for the same statement, but formulated with x ↦ - f x instead of -f.

      theorem MeasureTheory.Integrable.neg' {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} (hf : Integrable f μ) :
      Integrable (fun (x : α) => -f x) μ

      If f is integrable, then so is fun x ↦ - f x. See Integrable.neg for the same statement, but formulated with -f instead of fun x ↦ - f x.

      @[simp]
      theorem MeasureTheory.integrable_neg_iff {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} :
      @[simp]
      theorem MeasureTheory.integrable_add_iff_integrable_right {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f g : αβ} (hf : Integrable f μ) :
      Integrable (f + g) μ Integrable g μ

      if f is integrable, then f + g is integrable iff g is. See integrable_add_iff_integrable_right' for the same statement with fun x ↦ f x + g x instead of f + g.

      @[simp]
      theorem MeasureTheory.integrable_add_iff_integrable_right' {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f g : αβ} (hf : Integrable f μ) :
      Integrable (fun (x : α) => f x + g x) μ Integrable g μ

      if f is integrable, then fun x ↦ f x + g x is integrable iff g is. See integrable_add_iff_integrable_right for the same statement with f + g instead of fun x ↦ f x + g x.

      @[simp]
      theorem MeasureTheory.integrable_add_iff_integrable_left {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f g : αβ} (hf : Integrable f μ) :
      Integrable (g + f) μ Integrable g μ

      if f is integrable, then g + f is integrable iff g is. See integrable_add_iff_integrable_left' for the same statement with fun x ↦ g x + f x instead of g + f.

      @[simp]
      theorem MeasureTheory.integrable_add_iff_integrable_left' {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f g : αβ} (hf : Integrable f μ) :
      Integrable (fun (x : α) => g x + f x) μ Integrable g μ

      if f is integrable, then fun x ↦ g x + f x is integrable iff g is. See integrable_add_iff_integrable_left' for the same statement with g + f instead of fun x ↦ g x + f x.

      theorem MeasureTheory.integrable_left_of_integrable_add_of_nonneg {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f g : α} (h_meas : AEStronglyMeasurable f μ) (hf : 0 ≤ᶠ[ae μ] f) (hg : 0 ≤ᶠ[ae μ] g) (h_int : Integrable (f + g) μ) :
      theorem MeasureTheory.integrable_right_of_integrable_add_of_nonneg {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f g : α} (h_meas : AEStronglyMeasurable f μ) (hf : 0 ≤ᶠ[ae μ] f) (hg : 0 ≤ᶠ[ae μ] g) (h_int : Integrable (f + g) μ) :
      theorem MeasureTheory.integrable_add_iff_of_nonneg {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f g : α} (h_meas : AEStronglyMeasurable f μ) (hf : 0 ≤ᶠ[ae μ] f) (hg : 0 ≤ᶠ[ae μ] g) :
      theorem MeasureTheory.integrable_add_iff_of_nonpos {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f g : α} (h_meas : AEStronglyMeasurable f μ) (hf : f ≤ᶠ[ae μ] 0) (hg : g ≤ᶠ[ae μ] 0) :
      theorem MeasureTheory.integrable_add_const_iff {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [IsFiniteMeasure μ] {f : αβ} {c : β} :
      Integrable (fun (x : α) => f x + c) μ Integrable f μ
      theorem MeasureTheory.integrable_const_add_iff {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [IsFiniteMeasure μ] {f : αβ} {c : β} :
      Integrable (fun (x : α) => c + f x) μ Integrable f μ
      theorem MeasureTheory.Integrable.sub {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f g : αβ} (hf : Integrable f μ) (hg : Integrable g μ) :
      Integrable (f - g) μ
      theorem MeasureTheory.Integrable.sub' {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f g : αβ} (hf : Integrable f μ) (hg : Integrable g μ) :
      Integrable (fun (a : α) => f a - g a) μ
      theorem MeasureTheory.Integrable.norm {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} (hf : Integrable f μ) :
      Integrable (fun (a : α) => f a) μ
      theorem MeasureTheory.Integrable.inf {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {β : Type u_6} [NormedLatticeAddCommGroup β] {f g : αβ} (hf : Integrable f μ) (hg : Integrable g μ) :
      Integrable (f g) μ
      theorem MeasureTheory.Integrable.sup {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {β : Type u_6} [NormedLatticeAddCommGroup β] {f g : αβ} (hf : Integrable f μ) (hg : Integrable g μ) :
      Integrable (f g) μ
      theorem MeasureTheory.Integrable.abs {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {β : Type u_6} [NormedLatticeAddCommGroup β] {f : αβ} (hf : Integrable f μ) :
      Integrable (fun (a : α) => |f a|) μ
      theorem MeasureTheory.Integrable.bdd_mul {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {F : Type u_6} [NormedDivisionRing F] {f g : αF} (hint : Integrable g μ) (hm : AEStronglyMeasurable f μ) (hfbdd : ∃ (C : ), ∀ (x : α), f x C) :
      Integrable (fun (x : α) => f x * g x) μ
      theorem MeasureTheory.Integrable.essSup_smul {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {𝕜 : Type u_6} [NormedField 𝕜] [NormedSpace 𝕜 β] {f : αβ} (hf : Integrable f μ) {g : α𝕜} (g_aestronglyMeasurable : AEStronglyMeasurable g μ) (ess_sup_g : essSup (fun (x : α) => g x‖ₑ) μ ) :
      Integrable (fun (x : α) => g x f x) μ

      Hölder's inequality for integrable functions: the scalar multiplication of an integrable vector-valued function by a scalar function with finite essential supremum is integrable.

      theorem MeasureTheory.Integrable.smul_essSup {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {𝕜 : Type u_6} [NormedRing 𝕜] [Module 𝕜 β] [BoundedSMul 𝕜 β] {f : α𝕜} (hf : Integrable f μ) {g : αβ} (g_aestronglyMeasurable : AEStronglyMeasurable g μ) (ess_sup_g : essSup (fun (x : α) => g x‖ₑ) μ ) :
      Integrable (fun (x : α) => f x g x) μ

      Hölder's inequality for integrable functions: the scalar multiplication of an integrable scalar-valued function by a vector-value function with finite essential supremum is integrable.

      theorem MeasureTheory.integrable_norm_iff {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} (hf : AEStronglyMeasurable f μ) :
      Integrable (fun (a : α) => f a) μ Integrable f μ
      theorem MeasureTheory.integrable_of_norm_sub_le {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f₀ f₁ : αβ} {g : α} (hf₁_m : AEStronglyMeasurable f₁ μ) (hf₀_i : Integrable f₀ μ) (hg_i : Integrable g μ) (h : ∀ᵐ (a : α) μ, f₀ a - f₁ a g a) :
      Integrable f₁ μ
      theorem MeasureTheory.integrable_of_le_of_le {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f g₁ g₂ : α} (hf : AEStronglyMeasurable f μ) (h_le₁ : g₁ ≤ᶠ[ae μ] f) (h_le₂ : f ≤ᶠ[ae μ] g₂) (h_int₁ : Integrable g₁ μ) (h_int₂ : Integrable g₂ μ) :
      theorem MeasureTheory.Integrable.prod_mk {α : Type u_1} {β : Type u_2} {γ : Type u_3} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [NormedAddCommGroup γ] {f : αβ} {g : αγ} (hf : Integrable f μ) (hg : Integrable g μ) :
      Integrable (fun (x : α) => (f x, g x)) μ
      theorem MeasureTheory.Memℒp.integrable {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {q : ENNReal} (hq1 : 1 q) {f : αβ} [IsFiniteMeasure μ] (hfq : Memℒp f q μ) :
      theorem MeasureTheory.Integrable.measure_norm_ge_lt_top {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} (hf : Integrable f μ) {ε : } (hε : 0 < ε) :
      μ {x : α | ε f x} <

      A non-quantitative version of Markov inequality for integrable functions: the measure of points where ‖f x‖ ≥ ε is finite for all positive ε.

      theorem MeasureTheory.Integrable.measure_norm_gt_lt_top {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {f : αβ} (hf : Integrable f μ) {ε : } (hε : 0 < ε) :
      μ {x : α | ε < f x} <

      A non-quantitative version of Markov inequality for integrable functions: the measure of points where ‖f x‖ > ε is finite for all positive ε.

      theorem MeasureTheory.Integrable.measure_ge_lt_top {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : α} (hf : Integrable f μ) {ε : } (ε_pos : 0 < ε) :
      μ {a : α | ε f a} <

      If f is -valued and integrable, then for any c > 0 the set {x | f x ≥ c} has finite measure.

      theorem MeasureTheory.Integrable.measure_le_lt_top {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : α} (hf : Integrable f μ) {c : } (c_neg : c < 0) :
      μ {a : α | f a c} <

      If f is -valued and integrable, then for any c < 0 the set {x | f x ≤ c} has finite measure.

      theorem MeasureTheory.Integrable.measure_gt_lt_top {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : α} (hf : Integrable f μ) {ε : } (ε_pos : 0 < ε) :
      μ {a : α | ε < f a} <

      If f is -valued and integrable, then for any c > 0 the set {x | f x > c} has finite measure.

      theorem MeasureTheory.Integrable.measure_lt_lt_top {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : α} (hf : Integrable f μ) {c : } (c_neg : c < 0) :
      μ {a : α | f a < c} <

      If f is -valued and integrable, then for any c < 0 the set {x | f x < c} has finite measure.

      theorem MeasureTheory.LipschitzWith.integrable_comp_iff_of_antilipschitz {α : Type u_1} {β : Type u_2} {γ : Type u_3} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] [NormedAddCommGroup γ] {K K' : NNReal} {f : αβ} {g : βγ} (hg : LipschitzWith K g) (hg' : AntilipschitzWith K' g) (g0 : g 0 = 0) :
      theorem MeasureTheory.Integrable.real_toNNReal {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : α} (hf : Integrable f μ) :
      Integrable (fun (x : α) => (f x).toNNReal) μ
      theorem MeasureTheory.ofReal_toReal_ae_eq {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : αENNReal} (hf : ∀ᵐ (x : α) μ, f x < ) :
      (fun (x : α) => ENNReal.ofReal (f x).toReal) =ᶠ[ae μ] f
      theorem MeasureTheory.coe_toNNReal_ae_eq {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : αENNReal} (hf : ∀ᵐ (x : α) μ, f x < ) :
      (fun (x : α) => (f x).toNNReal) =ᶠ[ae μ] f
      theorem MeasureTheory.integrable_count_iff {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} [NormedAddCommGroup β] [MeasurableSingletonClass α] {f : αβ} :

      A function is integrable for the counting measure iff its norm is summable.

      theorem MeasureTheory.integrable_withDensity_iff_integrable_coe_smul {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {E : Type u_6} [NormedAddCommGroup E] [NormedSpace E] {f : αNNReal} (hf : Measurable f) {g : αE} :
      Integrable g (μ.withDensity fun (x : α) => (f x)) Integrable (fun (x : α) => (f x) g x) μ
      theorem MeasureTheory.integrable_withDensity_iff_integrable_smul {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {E : Type u_6} [NormedAddCommGroup E] [NormedSpace E] {f : αNNReal} (hf : Measurable f) {g : αE} :
      Integrable g (μ.withDensity fun (x : α) => (f x)) Integrable (fun (x : α) => f x g x) μ
      theorem MeasureTheory.integrable_withDensity_iff_integrable_smul' {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {E : Type u_6} [NormedAddCommGroup E] [NormedSpace E] {f : αENNReal} (hf : Measurable f) (hflt : ∀ᵐ (x : α) μ, f x < ) {g : αE} :
      Integrable g (μ.withDensity f) Integrable (fun (x : α) => (f x).toReal g x) μ
      theorem MeasureTheory.integrable_withDensity_iff_integrable_coe_smul₀ {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {E : Type u_6} [NormedAddCommGroup E] [NormedSpace E] {f : αNNReal} (hf : AEMeasurable f μ) {g : αE} :
      Integrable g (μ.withDensity fun (x : α) => (f x)) Integrable (fun (x : α) => (f x) g x) μ
      theorem MeasureTheory.integrable_withDensity_iff_integrable_smul₀ {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {E : Type u_6} [NormedAddCommGroup E] [NormedSpace E] {f : αNNReal} (hf : AEMeasurable f μ) {g : αE} :
      Integrable g (μ.withDensity fun (x : α) => (f x)) Integrable (fun (x : α) => f x g x) μ
      theorem MeasureTheory.integrable_withDensity_iff {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : αENNReal} (hf : Measurable f) (hflt : ∀ᵐ (x : α) μ, f x < ) {g : α} :
      Integrable g (μ.withDensity f) Integrable (fun (x : α) => g x * (f x).toReal) μ
      theorem MeasureTheory.memℒ1_smul_of_L1_withDensity {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {E : Type u_6} [NormedAddCommGroup E] [NormedSpace E] {f : αNNReal} (f_meas : Measurable f) (u : (Lp E 1 (μ.withDensity fun (x : α) => (f x)))) :
      Memℒp (fun (x : α) => f x u x) 1 μ
      noncomputable def MeasureTheory.withDensitySMulLI {α : Type u_1} {m : MeasurableSpace α} (μ : Measure α) {E : Type u_6} [NormedAddCommGroup E] [NormedSpace E] {f : αNNReal} (f_meas : Measurable f) :
      (Lp E 1 (μ.withDensity fun (x : α) => (f x))) →ₗᵢ[] (Lp E 1 μ)

      The map u ↦ f • u is an isometry between the L^1 spaces for μ.withDensity f and μ.

      Equations
      • One or more equations did not get rendered due to their size.
      Instances For
        @[simp]
        theorem MeasureTheory.withDensitySMulLI_apply {α : Type u_1} {m : MeasurableSpace α} (μ : Measure α) {E : Type u_6} [NormedAddCommGroup E] [NormedSpace E] {f : αNNReal} (f_meas : Measurable f) (u : (Lp E 1 (μ.withDensity fun (x : α) => (f x)))) :
        (withDensitySMulLI μ f_meas) u = Memℒp.toLp (fun (x : α) => f x u x)
        theorem MeasureTheory.mem_ℒ1_toReal_of_lintegral_ne_top {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : αENNReal} (hfm : AEMeasurable f μ) (hfi : ∫⁻ (x : α), f x μ ) :
        Memℒp (fun (x : α) => (f x).toReal) 1 μ
        theorem MeasureTheory.integrable_toReal_of_lintegral_ne_top {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : αENNReal} (hfm : AEMeasurable f μ) (hfi : ∫⁻ (x : α), f x μ ) :
        Integrable (fun (x : α) => (f x).toReal) μ
        theorem MeasureTheory.integrable_toReal_iff {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : αENNReal} (hf : AEMeasurable f μ) (hf_ne_top : ∀ᵐ (x : α) μ, f x ) :
        Integrable (fun (x : α) => (f x).toReal) μ ∫⁻ (x : α), f x μ
        theorem MeasureTheory.lintegral_ofReal_ne_top_iff_integrable {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : α} (hfm : AEStronglyMeasurable f μ) (hf : 0 ≤ᶠ[ae μ] f) :

        Lemmas used for defining the positive part of an function #

        theorem MeasureTheory.Integrable.pos_part {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : α} (hf : Integrable f μ) :
        Integrable (fun (a : α) => f a 0) μ
        theorem MeasureTheory.Integrable.neg_part {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {f : α} (hf : Integrable f μ) :
        Integrable (fun (a : α) => -f a 0) μ
        theorem MeasureTheory.Integrable.smul {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {𝕜 : Type u_6} [NormedAddCommGroup 𝕜] [SMulZeroClass 𝕜 β] [BoundedSMul 𝕜 β] (c : 𝕜) {f : αβ} (hf : Integrable f μ) :
        Integrable (c f) μ
        theorem IsUnit.integrable_smul_iff {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : MeasureTheory.Measure α} [NormedAddCommGroup β] {𝕜 : Type u_6} [NormedRing 𝕜] [Module 𝕜 β] [BoundedSMul 𝕜 β] {c : 𝕜} (hc : IsUnit c) (f : αβ) :
        theorem MeasureTheory.integrable_smul_iff {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {𝕜 : Type u_6} [NormedDivisionRing 𝕜] [Module 𝕜 β] [BoundedSMul 𝕜 β] {c : 𝕜} (hc : c 0) (f : αβ) :
        theorem MeasureTheory.Integrable.smul_of_top_right {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {𝕜 : Type u_6} [NormedRing 𝕜] [Module 𝕜 β] [BoundedSMul 𝕜 β] {f : αβ} {φ : α𝕜} (hf : Integrable f μ) (hφ : Memℒp φ μ) :
        Integrable (φ f) μ
        theorem MeasureTheory.Integrable.smul_of_top_left {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {𝕜 : Type u_6} [NormedRing 𝕜] [Module 𝕜 β] [BoundedSMul 𝕜 β] {f : αβ} {φ : α𝕜} (hφ : Integrable φ μ) (hf : Memℒp f μ) :
        Integrable (φ f) μ
        theorem MeasureTheory.Integrable.smul_const {α : Type u_1} {β : Type u_2} {m : MeasurableSpace α} {μ : Measure α} [NormedAddCommGroup β] {𝕜 : Type u_6} [NormedRing 𝕜] [Module 𝕜 β] [BoundedSMul 𝕜 β] {f : α𝕜} (hf : Integrable f μ) (c : β) :
        Integrable (fun (x : α) => f x c) μ
        theorem MeasureTheory.integrable_smul_const {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [NontriviallyNormedField 𝕜] [CompleteSpace 𝕜] {E : Type u_7} [NormedAddCommGroup E] [NormedSpace 𝕜 E] {f : α𝕜} {c : E} (hc : c 0) :
        Integrable (fun (x : α) => f x c) μ Integrable f μ
        theorem MeasureTheory.Integrable.const_mul {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [NormedRing 𝕜] {f : α𝕜} (h : Integrable f μ) (c : 𝕜) :
        Integrable (fun (x : α) => c * f x) μ
        theorem MeasureTheory.Integrable.const_mul' {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [NormedRing 𝕜] {f : α𝕜} (h : Integrable f μ) (c : 𝕜) :
        Integrable ((fun (x : α) => c) * f) μ
        theorem MeasureTheory.Integrable.mul_const {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [NormedRing 𝕜] {f : α𝕜} (h : Integrable f μ) (c : 𝕜) :
        Integrable (fun (x : α) => f x * c) μ
        theorem MeasureTheory.Integrable.mul_const' {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [NormedRing 𝕜] {f : α𝕜} (h : Integrable f μ) (c : 𝕜) :
        Integrable (f * fun (x : α) => c) μ
        theorem MeasureTheory.integrable_const_mul_iff {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [NormedRing 𝕜] {c : 𝕜} (hc : IsUnit c) (f : α𝕜) :
        Integrable (fun (x : α) => c * f x) μ Integrable f μ
        theorem MeasureTheory.integrable_mul_const_iff {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [NormedRing 𝕜] {c : 𝕜} (hc : IsUnit c) (f : α𝕜) :
        Integrable (fun (x : α) => f x * c) μ Integrable f μ
        theorem MeasureTheory.Integrable.bdd_mul' {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [NormedRing 𝕜] {f g : α𝕜} {c : } (hg : Integrable g μ) (hf : AEStronglyMeasurable f μ) (hf_bound : ∀ᵐ (x : α) μ, f x c) :
        Integrable (fun (x : α) => f x * g x) μ
        theorem MeasureTheory.Integrable.mul_of_top_right {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [NormedRing 𝕜] {f φ : α𝕜} (hf : Integrable f μ) (hφ : Memℒp φ μ) :
        Integrable (φ * f) μ
        theorem MeasureTheory.Integrable.mul_of_top_left {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [NormedRing 𝕜] {f φ : α𝕜} (hφ : Integrable φ μ) (hf : Memℒp f μ) :
        Integrable (φ * f) μ
        theorem MeasureTheory.Integrable.div_const {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [NormedDivisionRing 𝕜] {f : α𝕜} (h : Integrable f μ) (c : 𝕜) :
        Integrable (fun (x : α) => f x / c) μ
        theorem MeasureTheory.Integrable.ofReal {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [RCLike 𝕜] {f : α} (hf : Integrable f μ) :
        Integrable (fun (x : α) => (f x)) μ
        theorem MeasureTheory.Integrable.re_im_iff {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [RCLike 𝕜] {f : α𝕜} :
        Integrable (fun (x : α) => RCLike.re (f x)) μ Integrable (fun (x : α) => RCLike.im (f x)) μ Integrable f μ
        theorem MeasureTheory.Integrable.re {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [RCLike 𝕜] {f : α𝕜} (hf : Integrable f μ) :
        Integrable (fun (x : α) => RCLike.re (f x)) μ
        theorem MeasureTheory.Integrable.im {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {𝕜 : Type u_6} [RCLike 𝕜] {f : α𝕜} (hf : Integrable f μ) :
        Integrable (fun (x : α) => RCLike.im (f x)) μ
        theorem MeasureTheory.Integrable.trim {α : Type u_1} {m : MeasurableSpace α} {H : Type u_6} [NormedAddCommGroup H] {m0 : MeasurableSpace α} {μ' : Measure α} {f : αH} (hm : m m0) (hf_int : Integrable f μ') (hf : StronglyMeasurable f) :
        Integrable f (μ'.trim hm)
        theorem MeasureTheory.integrable_of_integrable_trim {α : Type u_1} {m : MeasurableSpace α} {H : Type u_6} [NormedAddCommGroup H] {m0 : MeasurableSpace α} {μ' : Measure α} {f : αH} (hm : m m0) (hf_int : Integrable f (μ'.trim hm)) :
        theorem MeasureTheory.integrable_of_forall_fin_meas_le' {α : Type u_1} {m : MeasurableSpace α} {E : Type u_6} {m0 : MeasurableSpace α} [NormedAddCommGroup E] {μ : Measure α} (hm : m m0) [SigmaFinite (μ.trim hm)] (C : ENNReal) (hC : C < ) {f : αE} (hf_meas : AEStronglyMeasurable f μ) (hf : ∀ (s : Set α), MeasurableSet sμ s ∫⁻ (x : α) in s, f x‖ₑ μ C) :
        theorem MeasureTheory.integrable_of_forall_fin_meas_le {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {E : Type u_6} [NormedAddCommGroup E] [SigmaFinite μ] (C : ENNReal) (hC : C < ) {f : αE} (hf_meas : AEStronglyMeasurable f μ) (hf : ∀ (s : Set α), MeasurableSet sμ s ∫⁻ (x : α) in s, f x‖ₑ μ C) :
        theorem MeasureTheory.Integrable.restrict {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {E : Type u_6} [NormedAddCommGroup E] {f : αE} (hf : Integrable f μ) {s : Set α} :
        Integrable f (μ.restrict s)

        One should usually use MeasureTheory.Integrable.IntegrableOn instead.

        theorem ContinuousLinearMap.integrable_comp {α : Type u_1} {m : MeasurableSpace α} {μ : MeasureTheory.Measure α} {E : Type u_6} [NormedAddCommGroup E] {𝕜 : Type u_7} [NontriviallyNormedField 𝕜] [NormedSpace 𝕜 E] {H : Type u_8} [NormedAddCommGroup H] [NormedSpace 𝕜 H] {φ : αH} (L : H →L[𝕜] E) (φ_int : MeasureTheory.Integrable φ μ) :
        MeasureTheory.Integrable (fun (a : α) => L (φ a)) μ
        @[simp]
        theorem ContinuousLinearEquiv.integrable_comp_iff {α : Type u_1} {m : MeasurableSpace α} {μ : MeasureTheory.Measure α} {E : Type u_6} [NormedAddCommGroup E] {𝕜 : Type u_7} [NontriviallyNormedField 𝕜] [NormedSpace 𝕜 E] {H : Type u_8} [NormedAddCommGroup H] [NormedSpace 𝕜 H] {φ : αH} (L : H ≃L[𝕜] E) :
        MeasureTheory.Integrable (fun (a : α) => L (φ a)) μ MeasureTheory.Integrable φ μ
        @[simp]
        theorem LinearIsometryEquiv.integrable_comp_iff {α : Type u_1} {m : MeasurableSpace α} {μ : MeasureTheory.Measure α} {E : Type u_6} [NormedAddCommGroup E] {𝕜 : Type u_7} [NontriviallyNormedField 𝕜] [NormedSpace 𝕜 E] {H : Type u_8} [NormedAddCommGroup H] [NormedSpace 𝕜 H] {φ : αH} (L : H ≃ₗᵢ[𝕜] E) :
        MeasureTheory.Integrable (fun (a : α) => L (φ a)) μ MeasureTheory.Integrable φ μ
        theorem MeasureTheory.Integrable.apply_continuousLinearMap {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {E : Type u_6} [NormedAddCommGroup E] {𝕜 : Type u_7} [NontriviallyNormedField 𝕜] [NormedSpace 𝕜 E] {H : Type u_8} [NormedAddCommGroup H] [NormedSpace 𝕜 H] {φ : αH →L[𝕜] E} (φ_int : Integrable φ μ) (v : H) :
        Integrable (fun (a : α) => (φ a) v) μ
        theorem MeasureTheory.Integrable.fst {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {E : Type u_6} {F : Type u_7} [NormedAddCommGroup E] [NormedSpace E] [NormedAddCommGroup F] [NormedSpace F] {f : αE × F} (hf : Integrable f μ) :
        Integrable (fun (x : α) => (f x).1) μ
        theorem MeasureTheory.Integrable.snd {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {E : Type u_6} {F : Type u_7} [NormedAddCommGroup E] [NormedSpace E] [NormedAddCommGroup F] [NormedSpace F] {f : αE × F} (hf : Integrable f μ) :
        Integrable (fun (x : α) => (f x).2) μ
        theorem MeasureTheory.integrable_prod {α : Type u_1} {m : MeasurableSpace α} {μ : Measure α} {E : Type u_6} {F : Type u_7} [NormedAddCommGroup E] [NormedSpace E] [NormedAddCommGroup F] [NormedSpace F] {f : αE × F} :
        Integrable f μ Integrable (fun (x : α) => (f x).1) μ Integrable (fun (x : α) => (f x).2) μ