fpvandoorn/carleson
Source indexedlemma · leanprover/lean4:v4.32.0
enorm_czApproximation_le_infinite
Carleson.TwoSidedCarleson.WeakCalderonZygmund · Carleson/TwoSidedCarleson/WeakCalderonZygmund.lean:844 to 869
Source documentation
Equation (10.2.17) specialized to the general case.
Exact Lean statement
lemma enorm_czApproximation_le_infinite {hf : BoundedFiniteSupport f} (hX : GeneralCase f α) :
∀ᵐ x, ‖czApproximation f α x‖ₑ ≤ 2 ^ (3 * a) * αComplete declaration
Lean source
Full Lean sourceLean 4
lemma enorm_czApproximation_le_infinite {hf : BoundedFiniteSupport f} (hX : GeneralCase f α) : ∀ᵐ x, ‖czApproximation f α x‖ₑ ≤ 2 ^ (3 * a) * α := by have h₁ (x : X) (hx : ∃ i, x ∈ czPartition hX i) : ‖czApproximation f α x‖ₑ ≤ 2 ^ (3 * a) * α := have ⟨i, hi⟩ := hx calc ‖czApproximation f α x‖ₑ _ = ‖⨍ x in czPartition hX i, f x‖ₑ := by rw [czApproximation_def_of_mem hi] _ ≤ ⨍⁻ x in czPartition hX i, ‖f x‖ₑ ∂volume := enorm_integral_le_lintegral_enorm _ _ ≤ (volume (czPartition hX i))⁻¹ * ∫⁻ x in czPartition hX i, ‖f x‖ₑ := by simp [laverage] _ ≤ 2 ^ (3 * a) * (volume (czBall7 hX i))⁻¹ * ∫⁻ x in czPartition hX i, ‖f x‖ₑ := by apply mul_le_mul_left have := (ENNReal.inv_mul_le_iff (by simp) (by simp)).mpr <| volume_czBall7_le hX i rwa [← ENNReal.inv_le_inv, ENNReal.mul_inv (by simp) (by simp), inv_inv] at this _ ≤ 2 ^ (3 * a) * (volume (czBall7 hX i))⁻¹ * ∫⁻ x in czBall7 hX i, ‖f x‖ₑ := mul_le_mul_right (lintegral_mono_set czPartition_subset_czBall7) _ _ ≤ 2 ^ (3 * a) * α := by rw [mul_assoc]; gcongr; simpa [laverage] using laverage_czBall7_le hX i have h₂ : ∀ᵐ x, ¬(∃ i, x ∈ czPartition hX i) → ‖czApproximation f α x‖ₑ ≤ 2 ^ (3 * a) * α := (lebesgue_differentiation hf).mono fun x ⟨c, r, lim, _, x_mem_ball⟩ hx ↦ by have le_α := hx rw [← mem_iUnion, iUnion_czPartition, mem_preimage, mem_Ioi, not_lt] at le_α simp only [czApproximation, hX, reduceDIte, hx] refine le_of_tendsto lim.enorm <| Eventually.of_forall fun i ↦ ?_ apply le_trans (enorm_integral_le_lintegral_enorm f) exact le_trans (laverage_le_globalMaximalFunction (x_mem_ball i)) <| le_α.trans α_le_mul_α simpa only [← or_imp, em, forall_const] using eventually_and.mpr ⟨Eventually.of_forall h₁, h₂⟩