AlexKontorovich/PrimeNumberTheoremAnd
Source indexedtheorem · leanprover/lean4:v4.32.0
Ramanujan.integrable_theta
PrimeNumberTheoremAnd.IEANTN.Ramanujan.RamanujanCalculations · PrimeNumberTheoremAnd/IEANTN/Ramanujan/RamanujanCalculations.lean:414 to 425
Mathematical statement
Exact Lean statement
theorem integrable_theta (x : ℝ) :
IntegrableOn (fun t ↦ (θ t - t) / (t * log t ^ 2)) (Icc 2 x) volumeComplete declaration
Lean source
Full Lean sourceLean 4
theorem integrable_theta (x : ℝ) : IntegrableOn (fun t ↦ (θ t - t) / (t * log t ^ 2)) (Icc 2 x) volume := by have l0 : ContinuousOn (fun t ↦ (t * log t ^ 2)⁻¹) (Set.Icc 2 x) := by refine ContinuousOn.inv₀ (continuousOn_id.mul (ContinuousOn.pow (ContinuousOn.log continuousOn_id fun y hy ↦ ?_) 2)) fun y hy ↦ ?_ repeat simp_all; grind have l1 : IntegrableOn (fun t ↦ θ t / (t * log t ^ 2)) (Icc 2 x) volume := (theta_mono.monotoneOn _).integrableOn_isCompact isCompact_Icc |>.mul_continuousOn l0 isCompact_Icc have l2 : IntegrableOn (fun t ↦ t / (t * log t ^ 2)) (Icc 2 x) volume := monotoneOn_id.integrableOn_isCompact isCompact_Icc |>.mul_continuousOn l0 isCompact_Icc simpa [div_sub_div_same] using! l1.sub' l2