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fpvandoorn/carleson
Source indexedlemma Β· leanprover/lean4:v4.32.0

dens2_antichain

Carleson.Antichain.Basic Β· Carleson/Antichain/Basic.lean:424 to 458

Source documentation

Lemma 6.1.3 (inequality 6.1.11).

Exact Lean statement

lemma dens2_antichain {𝔄 : Set (𝔓 X)} (h𝔄 : IsAntichain (Β· ≀ Β·) 𝔄)
    {f : X β†’ β„‚} (hfF : βˆ€ x, β€–f xβ€– ≀ F.indicator 1 x) (hf : Measurable f)
    {g : X β†’ β„‚} (hgG : βˆ€ x, β€–g xβ€– ≀ G.indicator 1 x) (hg : Measurable g) :
    β€–βˆ« x, ((starRingEnd β„‚) (g x)) * carlesonSum 𝔄 f xβ€–β‚‘ ≀
      (C6_1_3 a nnq) * (densβ‚‚ (𝔄 : Set (𝔓 X))) ^ ((nnqt : ℝ)⁻¹ - 2⁻¹) *
        eLpNorm f 2 * eLpNorm g 2

Complete declaration

Lean source

Canonical source
Full Lean sourceLean 4
lemma dens2_antichain {𝔄 : Set (𝔓 X)} (h𝔄 : IsAntichain (Β· ≀ Β·) 𝔄)    {f : X β†’ β„‚} (hfF : βˆ€ x, β€–f xβ€– ≀ F.indicator 1 x) (hf : Measurable f)    {g : X β†’ β„‚} (hgG : βˆ€ x, β€–g xβ€– ≀ G.indicator 1 x) (hg : Measurable g) :    β€–βˆ« x, ((starRingEnd β„‚) (g x)) * carlesonSum 𝔄 f xβ€–β‚‘ ≀      (C6_1_3 a nnq) * (densβ‚‚ (𝔄 : Set (𝔓 X))) ^ ((nnqt : ℝ)⁻¹ - 2⁻¹) *        eLpNorm f 2 * eLpNorm g 2 := by  have bf := bcs_of_measurable_of_le_indicator_f hf hfF  have bg := bcs_of_measurable_of_le_indicator_g hg hgG  apply le_trans <| enorm_integral_le_lintegral_enorm _  simp_rw [enorm_mul]  let p' := ((qt X)⁻¹ - 2⁻¹)⁻¹  have hp'_inv : p'⁻¹ = 2⁻¹ * q⁻¹ := by simp only [p', inv_inv, qt, inv_nnqt_eq]; simp  have hpp : (p X).HolderConjugate p' := by    refine Real.holderConjugate_iff.mpr ⟨one_lt_p X, ?_⟩    rw [hp'_inv, inv_p_eq X, div_eq_mul_inv, inv_qt_eq]    ring  let C2_0_6' := C2_0_6 (defaultA a) (p X).toNNReal 2  have := eLpNorm_π“œ_le_eLpNorm_π“œp_mul 𝔄 hf hfF hpp  have := eLpNorm_π“œp_le 𝔄 <| bf.memLp 2  calc    _ ≀ eLpNorm g 2 * eLpNorm (carlesonSum 𝔄 f) 2 := by      simpa [RCLike.enorm_conj, ← eLpNorm_enorm] using lintegral_mul_le_eLpNorm_mul_eLqNorm        inferInstance bg.enorm.aestronglyMeasurable.aemeasurable          bf.carlesonSum.enorm.aestronglyMeasurable.aemeasurable    _ ≀ eLpNorm g 2 * (C6_1_2 a * eLpNorm (π“œ 𝔄 f) 2) := by      gcongr      exact eLpNorm_le_mul_eLpNorm_of_ae_le_mul'        (ae_of_all _ <| fun x ↦ maximal_bound_antichain h𝔄 hf x) 2    _ ≀ eLpNorm g 2 * (C6_1_2 a * ((densβ‚‚ 𝔄) ^ (p'⁻¹) * eLpNorm (π“œp 𝔄 (p X) f) 2)) := by gcongr    _ ≀ eLpNorm g 2 * (C6_1_2 a * ((densβ‚‚ 𝔄) ^ (p'⁻¹) * (C2_0_6' * eLpNorm f 2))) := by gcongr    _ = (C6_1_2 a * C2_0_6') * (densβ‚‚ 𝔄) ^ (p'⁻¹) * eLpNorm f 2 * eLpNorm g 2 := by ring    _ ≀ _ := by      gcongr ?_ * ?_ * eLpNorm f 2 _ * eLpNorm g 2 _      Β· exact_mod_cast const_check      Β· rw [hp'_inv, inv_nnqt_eq]; simp