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fpvandoorn/carleson
Source indexedtheorem · leanprover/lean4:v4.32.0

MeasureTheory.eLpNorm_le_eLpNorm_top_mul_eLpNorm'

Carleson.ToMathlib.MeasureTheory.Function.LpSeminorm.CompareExp · Carleson/ToMathlib/MeasureTheory/Function/LpSeminorm/CompareExp.lean:31 to 59

Mathematical statement

Exact Lean statement

theorem eLpNorm_le_eLpNorm_top_mul_eLpNorm' (p : ℝ≥0∞) (f : α → E) {g : α → F}
    (hg : AEStronglyMeasurable g μ) (b : E → F → G) (c : ℝ≥0)
    (h : ∀ᵐ x ∂μ, ‖b (f x) (g x)‖ₑ ≤ c * ‖f x‖ₑ * ‖g x‖ₑ) :
    eLpNorm (fun x => b (f x) (g x)) p μ ≤ c * eLpNorm f ∞ μ * eLpNorm g p μ

Complete declaration

Lean source

Canonical source
Full Lean sourceLean 4
theorem eLpNorm_le_eLpNorm_top_mul_eLpNorm' (p : 0∞) (f : α  E) {g : α  F}    (hg : AEStronglyMeasurable g μ) (b : E  F  G) (c : 0)    (h : ᵐ x ∂μ, ‖b (f x) (g x)‖ₑ  c * ‖f x‖ₑ * ‖g x‖ₑ) :    eLpNorm (fun x => b (f x) (g x)) p μ  c * eLpNorm f ∞ μ * eLpNorm g p μ := by  calc    eLpNorm (fun x => b (f x) (g x)) p μ  eLpNorm (fun x => c • ‖f x‖ₑ * ‖g x‖ₑ) p μ :=      eLpNorm_mono_enorm_ae h    _  c * eLpNorm f ∞ μ * eLpNorm g p μ := ?_  simp only [smul_mul_assoc,  Pi.smul_def]  apply eLpNorm_const_smul_le''.trans  simp only [enorm_NNReal]  rw [mul_assoc]  gcongr  obtain (rfl | rfl | hp) := ENNReal.trichotomy p  · simp  · rw [ eLpNorm_enorm f,  eLpNorm_enorm g]    simp_rw [eLpNorm_exponent_top, eLpNormEssSup_eq_essSup_enorm]    exact ENNReal.essSup_mul_le (‖f ·‖ₑ) (‖g ·‖ₑ)  obtain hp₁, hp₂ := ENNReal.toReal_pos_iff.mp hp  simp_rw [eLpNorm_eq_lintegral_rpow_enorm_toReal hp₁.ne' hp₂.ne, eLpNorm_exponent_top,    eLpNormEssSup, one_div, ENNReal.rpow_inv_le_iff hp]  simp only [enorm_eq_self]  rw [ENNReal.mul_rpow_of_nonneg (hz := hp.le), ENNReal.rpow_inv_rpow hp.ne',     lintegral_const_mul'' _ (by fun_prop)]  simp only [ ENNReal.mul_rpow_of_nonneg (hz := hp.le)]  apply lintegral_mono_ae  filter_upwards [h, enorm_ae_le_eLpNormEssSup f μ] with x hb hf  gcongr  exact hf