teorth/PFR
Source indexedlemma · leanprover/lean4:v4.33.0-rc1
multiTau_min_sum_le
PFR.MultiTauFunctional · PFR/MultiTauFunctional.lean:162 to 196
Source documentation
If is a -minimizer, then .
Exact Lean statement
lemma multiTau_min_sum_le {G Ω₀ : Type u} [hG : MeasurableFinGroup G] [hΩ₀ : MeasureSpace Ω₀]
(p : multiRefPackage G Ω₀) (Ω : Fin p.m → Type u) (hΩ : ∀ i, MeasureSpace (Ω i))
(hprobΩ : ∀ i, IsProbabilityMeasure (ℙ : Measure (Ω i))) (X : ∀ i, Ω i → G)
(hX : ∀ i, Measurable (X i)) (h_min : multiTauMinimizes p Ω hΩ X) :
∑ i, d[X i # p.X₀] ≤ 2 * p.m * p.η⁻¹ * d[p.X₀ # p.X₀]Complete declaration
Lean source
Full Lean sourceLean 4
lemma multiTau_min_sum_le {G Ω₀ : Type u} [hG : MeasurableFinGroup G] [hΩ₀ : MeasureSpace Ω₀] (p : multiRefPackage G Ω₀) (Ω : Fin p.m → Type u) (hΩ : ∀ i, MeasureSpace (Ω i)) (hprobΩ : ∀ i, IsProbabilityMeasure (ℙ : Measure (Ω i))) (X : ∀ i, Ω i → G) (hX : ∀ i, Measurable (X i)) (h_min : multiTauMinimizes p Ω hΩ X) : ∑ i, d[X i # p.X₀] ≤ 2 * p.m * p.η⁻¹ * d[p.X₀ # p.X₀] := by have hη : p.η > 0 := p.hη have hm : p.m > 0 := by linarith [p.hm] have hprob := p.hprob calc _ = p.η⁻¹ * (0 + p.η * ∑ i, d[X i # p.X₀]) := by simp; field_simp _ ≤ p.η⁻¹ * (D[X ; hΩ] + p.η * ∑ i, d[X i # p.X₀]) := by gcongr exact multiDist_nonneg hΩ hprobΩ X hX _ ≤ p.η⁻¹ * (D[fun _ ↦ p.X₀ ; fun _ ↦ hΩ₀] + p.η * (p.m * d[p.X₀ # p.X₀])) := by apply mul_le_mul_of_nonneg_left · have ineq := h_min (fun _ ↦ Ω₀) (fun _ ↦ hΩ₀) (fun _ ↦ hprob) (fun _ ↦ p.X₀) (fun _ ↦ p.hmeas) simp only [multiTau, Finset.sum_const, Finset.card_univ, Fintype.card_fin, nsmul_eq_mul] at ineq exact ineq exact inv_nonneg_of_nonneg (le_of_lt hη) _ ≤ p.η⁻¹ * (p.m * d[p.X₀ # p.X₀] + 1 * (p.m * d[p.X₀ # p.X₀])) := by gcongr · have : NeZero p.m := ⟨hm.ne'⟩ apply multidist_ruzsa_III p.hm (fun _ ↦ hΩ₀) (fun _ ↦ p.X₀) _ (fun _ ↦ p.hmeas) (fun _ ↦ p.hprob) _ 0 · intro _ _ simpa using .refl p.hmeas.aemeasurable intro _; infer_instance · have : 0 ≤ d[p.X₀ # p.X₀] := rdist_nonneg p.hmeas p.hmeas positivity exact p.hη' _ = _ := by field_simp ring