fpvandoorn/carleson
Source indexedlemma · leanprover/lean4:v4.32.0
MeasureTheory.value_lintegral_res₀
Carleson.ToMathlib.RealInterpolation.Misc · Carleson/ToMathlib/RealInterpolation/Misc.lean:1151 to 1179
Mathematical statement
Exact Lean statement
lemma value_lintegral_res₀ {j : Bool} {β : ℝ≥0∞} {γ : ℝ} (hγ : if j then γ > -1 else γ < -1) :
∫⁻ s : ℝ in res j β, ENNReal.ofReal (s ^ γ) = β ^ (γ + 1) / ENNReal.ofReal |γ + 1|Complete declaration
Lean source
Full Lean sourceLean 4
lemma value_lintegral_res₀ {j : Bool} {β : ℝ≥0∞} {γ : ℝ} (hγ : if j then γ > -1 else γ < -1) : ∫⁻ s : ℝ in res j β, ENNReal.ofReal (s ^ γ) = β ^ (γ + 1) / ENNReal.ofReal |γ + 1| := by · unfold res split at hγ <;> rename_i xor_split · rw [xor_split] simp only [↓reduceIte] split_ifs with htop · rw [htop, top_rpow_def] split_ifs · simp [lintegral_rpow_Ioi_top, top_div_of_lt_top] · linarith · linarith · by_cases hzero : β = 0 · rw [hzero, ENNReal.zero_rpow_of_pos (by linarith)]; simp · have htcinv : 0 < β.toReal := toReal_pos hzero htop rw [lintegral_rpow_of_gt_abs htcinv.le hγ, ENNReal.ofReal_div_of_pos (by rw [abs_pos]; linarith), ← ENNReal.ofReal_rpow_of_pos htcinv, ofReal_toReal_eq_iff.mpr htop] · simp only [eq_false_of_ne_true xor_split, Bool.false_eq_true, ↓reduceIte] split_ifs with htop · rw [htop, top_rpow_of_neg (by linarith)]; simp · by_cases hzero : β = 0 · rw [hzero, toReal_zero, lintegral_rpow_Ioi_top, zero_rpow_of_neg (by linarith), top_div_of_lt_top] exact coe_lt_top · have htcinv : 0 < β.toReal := toReal_pos hzero htop rw [lintegral_Ioi_rpow_of_lt_abs htcinv hγ, ofReal_div_of_pos (by rw [abs_pos]; linarith), ← ofReal_rpow_of_pos htcinv, ofReal_toReal_eq_iff.mpr htop]