Estimation.CATE.OrthogonalLearning.LocalEmpProcess
Empirical-process modulus results for the CATE DR-Learner: Rademacher, localized, honest-split, random-nuisance, and end-to-end oracle bounds.
DRLearner 5 core · 1 supporting This file proves that bounded outcomes, bounded target evaluations, strict propensity overlap, bounded nuisance regressions, and a Rademacher-complexity bound imply the local empirical-process modulus for the doubly robu ★ localEmpProcessModulus_drLearner
DR-Learner Empirical Modulus
This file proves that bounded outcomes, bounded target evaluations, strict
propensity overlap, bounded nuisance regressions, and a Rademacher-complexity
bound imply the local empirical-process modulus for the doubly robust learner
for conditional treatment effects. It connects the generic orthogonal
statistical-learning modulus to the causal conditional-effect system through
the assumption predicates DREvalBounded, DROutcomeBounded,
DRNuisanceOverlap, and DRNuisanceMuBounded, the bounded-loss bridge
dr_loss_uniformly_bounded, and the modulus theorem
localEmpProcessModulus_drLearner.
Boundedness of the target candidate evaluation map: |eval θ x| ≤ M_Θ uniformly over θ ∈ Θ_set and x : γ.
Definition (Lean source)
Bounded outcome assumption: the outcome coordinate is bounded by M_Y under the observed-data law P_Z, almost everywhere.
Definition (Lean source)
Strict overlap floor on the realised nuisance h: the propensity component h.e_fn is bounded inside [ε, 1 − ε] uniformly in x.
Definition (Lean source)
Uniform L∞-bound on the outcome-regression component of the realised nuisance h: |h.μ_fn b x| ≤ M_μ for both treatment arms.
Definition (Lean source)
DR-Learner bounded-loss Rademacher modulus. Consider the doubly robust orthogonal-learning system for conditional treatment effects, cross-fitted via a one-shot sample split, whose truth-identifying candidate belongs to the target set, has a measurable evaluation map, and recovers the population CATE function through that evaluation map. Suppose the candidate evaluation maps are uniformly bounded, the observed outcome is almost-surely bounded, the realised nuisance outcome-regression is uniformly bounded on both treatment arms, and the realised propensity stays away from 0 and 1 by a fixed margin; suppose also that the resulting doubly robust loss is continuous in the candidate over the target set at that realised nuisance, a sequence R n bounds the Rademacher complexity of the centred loss class on the estimation fold, the truth-identifying candidate still minimizes the clamped population loss at the realised nuisance, and the confidence level δ lies strictly above 0 and at most 1. Then there is a nonnegative constant b for which the system obeys the local empirical-process modulus condition at the explicit rate ρ n = √(2 R n + 2b · √(2 log(1/δ) / |B(n)|)) on nonempty estimation folds, with boundary value ρ n = √(2b) on empty folds.
Formal statement
Proof (Lean source)
1 supporting declaration (lemmas, instances)
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dr_loss_uniformly_boundedtheorem — Bridge: DR-Learner squared loss is bounded under (M_Θ, M_Y, M_μ, ε).hypothesesIsFiniteMeasure P.μS :Θ :Θ_set :Set ΘΘ_convex :Convex ℝ Θ_setθ₀ :Θθ₀_mem :θ₀ ∈ Θ_seteval :Θ → γ → ℝeval_meas :∀ θ, Measurable (eval θ)eval_θ₀ :∀ x, eval θ₀ x = S.τ_val xθ₀_minimizes :DRThetaMinimizes S Θ_set θ₀ evalM_Θ M_Y M_μ ε :ℝhM_Θ :DREvalBounded Θ_set eval M_ΘhM_Y :DROutcomeBounded S M_Yh :hM_μ :DRNuisanceMuBounded h M_μhOverlap :DRNuisanceOverlap S Θ_set h εconclusionUniformlyBoundedLossAE (drLearningSystem S Θ Θ_set Θ_convex θ₀ θ₀_mem eval eval_meas eval_θ₀ θ₀_minimizes) h ((M_Θ + 2 * M_μ + 2 * (M_Y + M_μ) / ε) ^ 2)Proof (Lean source)
theorem dr_loss_uniformly_bounded [StandardBorelSpace P.Ω] [IsFiniteMeasure P.μ] (S : CATEEstimationSystem P γ) (Θ : Type*) [NormedAddCommGroup Θ] [InnerProductSpace ℝ Θ] (Θ_set : Set Θ) (Θ_convex : Convex ℝ Θ_set) (θ₀ : Θ) (θ₀_mem : θ₀ ∈ Θ_set) (eval : Θ → γ → ℝ) (eval_meas : ∀ θ, Measurable (eval θ)) (eval_θ₀ : ∀ x, eval θ₀ x = S.τ_val x) (θ₀_minimizes : DRThetaMinimizes S Θ_set θ₀ eval) {M_Θ M_Y M_μ ε : ℝ} (hM_Θ : DREvalBounded Θ_set eval M_Θ) (hM_Y : DROutcomeBounded S M_Y) (h : NuisanceVec γ) (hM_μ : DRNuisanceMuBounded h M_μ) (hOverlap : DRNuisanceOverlap S Θ_set h ε) : UniformlyBoundedLossAE (drLearningSystem S Θ Θ_set Θ_convex θ₀ θ₀_mem eval eval_meas eval_θ₀ θ₀_minimizes) h ((M_Θ + 2 * M_μ + 2 * (M_Y + M_μ) / ε) ^ 2) := by let Mφ : ℝ := 2 * M_μ + 2 * (M_Y + M_μ) / ε have hMφ_eq : M_Θ + 2 * M_μ + 2 * (M_Y + M_μ) / ε = M_Θ + Mφ := by change M_Θ + 2 * M_μ + 2 * (M_Y + M_μ) / ε = M_Θ + (2 * M_μ + 2 * (M_Y + M_μ) / ε) ring rw [hMφ_eq] rcases hM_Θ with ⟨hMΘ_nonneg, hEval⟩ rcases hM_Y with ⟨hMY_nonneg, hY_ae⟩ rcases hM_μ with ⟨hMμ_nonneg, hMu⟩ rcases hOverlap with ⟨hε_pos, _hε_half, hOverlap'⟩ filter_upwards [hY_ae] with z hz intro θ hθ let x : γ := z.1 let I : ℝ := BackdoorEstimationSystem.indA z have hI_nonneg : 0 ≤ I := by by_cases hz : z.2.1 = true · simp [I, BackdoorEstimationSystem.indA, BackdoorEstimationSystem.projA, hz] · simp [I, BackdoorEstimationSystem.indA, BackdoorEstimationSystem.projA, hz] have hI_le_one : I ≤ 1 := by by_cases hz : z.2.1 = true · simp [I, BackdoorEstimationSystem.indA, BackdoorEstimationSystem.projA, hz] · simp [I, BackdoorEstimationSystem.indA, BackdoorEstimationSystem.projA, hz] have hOneSubI_nonneg : 0 ≤ 1 - I := by linarith have hOneSubI_le_one : 1 - I ≤ 1 := by linarith have he_lower : ε ≤ h.e_fn x := (hOverlap' x).1 have he_upper : h.e_fn x ≤ 1 - ε := (hOverlap' x).2 have he_pos : 0 < h.e_fn x := lt_of_lt_of_le hε_pos he_lower have hden_lower : ε ≤ 1 - h.e_fn x := by linarith have hden_pos : 0 < 1 - h.e_fn x := lt_of_lt_of_le hε_pos hden_lower have hsum_nonneg : 0 ≤ M_Y + M_μ := by linarith have hdiff_mu : |h.μ_fn true x - h.μ_fn false x| ≤ 2 * M_μ := by have htri := abs_sub (h.μ_fn true x) (h.μ_fn false x) have ht := hMu true x have hf := hMu false x nlinarith have hres_true : |z.2.2 - h.μ_fn true x| ≤ M_Y + M_μ := by have htri := abs_sub z.2.2 (h.μ_fn true x) have hy := hz have hm := hMu true x nlinarith have hres_false : |z.2.2 - h.μ_fn false x| ≤ M_Y + M_μ := by have htri := abs_sub z.2.2 (h.μ_fn false x) have hy := hz have hm := hMu false x nlinarith have hratio_true : |I / h.e_fn x| ≤ 1 / ε := by have hinv_le : (h.e_fn x)⁻¹ ≤ ε⁻¹ := (inv_le_inv₀ he_pos hε_pos).2 he_lower have hmul₁ : I * (h.e_fn x)⁻¹ ≤ 1 * (h.e_fn x)⁻¹ := mul_le_mul_of_nonneg_right hI_le_one (inv_nonneg.mpr he_pos.le) have hmul₂ : 1 * (h.e_fn x)⁻¹ ≤ 1 * ε⁻¹ := mul_le_mul_of_nonneg_left hinv_le zero_le_one have hmul : I * (h.e_fn x)⁻¹ ≤ 1 * ε⁻¹ := le_trans hmul₁ hmul₂ simpa [div_eq_mul_inv, one_div, abs_of_nonneg hI_nonneg, abs_of_pos he_pos] using hmul have hratio_false : |(1 - I) / (1 - h.e_fn x)| ≤ 1 / ε := by have hinv_le : (1 - h.e_fn x)⁻¹ ≤ ε⁻¹ := (inv_le_inv₀ hden_pos hε_pos).2 hden_lower have hmul₁ : (1 - I) * (1 - h.e_fn x)⁻¹ ≤ 1 * (1 - h.e_fn x)⁻¹ := mul_le_mul_of_nonneg_right hOneSubI_le_one (inv_nonneg.mpr hden_pos.le) have hmul₂ : 1 * (1 - h.e_fn x)⁻¹ ≤ 1 * ε⁻¹ := mul_le_mul_of_nonneg_left hinv_le zero_le_one have hmul : (1 - I) * (1 - h.e_fn x)⁻¹ ≤ 1 * ε⁻¹ := le_trans hmul₁ hmul₂ simpa [div_eq_mul_inv, one_div, abs_of_nonneg hOneSubI_nonneg, abs_of_pos hden_pos] using hmul have hterm_true : |(I / h.e_fn x) * (z.2.2 - h.μ_fn true x)| ≤ (M_Y + M_μ) / ε := by rw [abs_mul] have hmul := mul_le_mul hratio_true hres_true (abs_nonneg _) (one_div_nonneg.mpr hε_pos.le) simpa [div_eq_mul_inv, one_div, mul_comm, mul_left_comm, mul_assoc] using hmul have hterm_false : |((1 - I) / (1 - h.e_fn x)) * (z.2.2 - h.μ_fn false x)| ≤ (M_Y + M_μ) / ε := by rw [abs_mul] have hmul := mul_le_mul hratio_false hres_false (abs_nonneg _) (one_div_nonneg.mpr hε_pos.le) simpa [div_eq_mul_inv, one_div, mul_comm, mul_left_comm, mul_assoc] using hmul have hphi : |phi_eta z h| ≤ Mφ := by have htri₁ := abs_sub ((h.μ_fn true x - h.μ_fn false x) + (I / h.e_fn x) * (z.2.2 - h.μ_fn true x)) (((1 - I) / (1 - h.e_fn x)) * (z.2.2 - h.μ_fn false x)) have htri₂ := abs_add_le (h.μ_fn true x - h.μ_fn false x) ((I / h.e_fn x) * (z.2.2 - h.μ_fn true x)) have hraw : |(h.μ_fn true x - h.μ_fn false x) + (I / h.e_fn x) * (z.2.2 - h.μ_fn true x) - ((1 - I) / (1 - h.e_fn x)) * (z.2.2 - h.μ_fn false x)| ≤ 2 * M_μ + (M_Y + M_μ) / ε + (M_Y + M_μ) / ε := by nlinarith have hraw' : |(h.μ_fn true x - h.μ_fn false x) + (I / h.e_fn x) * (z.2.2 - h.μ_fn true x) - ((1 - I) / (1 - h.e_fn x)) * (z.2.2 - h.μ_fn false x) - 0| ≤ Mφ := by have hraw₀ : |(h.μ_fn true x - h.μ_fn false x) + (I / h.e_fn x) * (z.2.2 - h.μ_fn true x) - ((1 - I) / (1 - h.e_fn x)) * (z.2.2 - h.μ_fn false x) - 0| ≤ 2 * M_μ + (M_Y + M_μ) / ε + (M_Y + M_μ) / ε := by simpa using hraw calc |(h.μ_fn true x - h.μ_fn false x) + (I / h.e_fn x) * (z.2.2 - h.μ_fn true x) - ((1 - I) / (1 - h.e_fn x)) * (z.2.2 - h.μ_fn false x) - 0| ≤ 2 * M_μ + (M_Y + M_μ) / ε + (M_Y + M_μ) / ε := hraw₀ _ = Mφ := by dsimp [Mφ] ring simpa [phi_eta, BackdoorEstimationSystem.aipwMoment, BackdoorEstimationSystem.projX, BackdoorEstimationSystem.projY, x, I] using hraw' have hdiff_loss : |phi_eta z h - eval θ z.1| ≤ Mφ + M_Θ := by have htri := abs_sub (phi_eta z h) (eval θ z.1) have heval := hEval θ hθ z.1 nlinarith have hsq : (phi_eta z h - eval θ z.1) ^ 2 ≤ (M_Θ + Mφ) ^ 2 := by have hbound : |phi_eta z h - eval θ z.1| ≤ M_Θ + Mφ := by linarith have hneg : -(M_Θ + Mφ) ≤ |phi_eta z h - eval θ z.1| := by have hnonneg := abs_nonneg (phi_eta z h - eval θ z.1) nlinarith simpa [sq_abs] using sq_le_sq' hneg hbound have hloss_nonneg : 0 ≤ (phi_eta z h - eval θ z.1) ^ 2 := sq_nonneg _ simpa [UniformlyBoundedLossAE, drLearningSystem, abs_of_nonneg hloss_nonneg] using hsq
LocalizedDRLearner 2 core · 1 supporting This file applies the localized empirical-process modulus theorem to the DR-Learner for conditional average treatment effects. ★ localEmpProcessModulus_localized_drLearner
Localized Modulus for the DR-Learner
This file applies the localized empirical-process modulus theorem to the DR-Learner for conditional average treatment effects. It formulates the critical-radius hypothesis for the centered quadratic DR-loss class and derives both the sharp localized modulus and a bounded-loss fallback modulus.
Critical-radius hypothesis for the DR-Learner.
Definition (Lean source)
DR-Learner localized modulus, sharp Foster–Syrgkanis form. For the DR-Learner CATE estimation system, suppose the evaluation functional is measurable in its parameter and recovers the true CATE at a parameter θ₀ in the constraint set, and that the evaluation functional, outcome, and fixed nuisance conditional-mean are uniformly bounded while the nuisance's propensity score satisfies ε-overlap. Assume the centred DR-loss is continuous in θ, a clamped version of θ₀ minimizes it, its population Rademacher complexity along a dense index sequence is controlled by a sub-root envelope ψ with respect to a seminorm that is invariant under almost-everywhere modification, and the same Rademacher upper bound extends to loss differences across the whole constraint set, together with Lipschitz and diameter control of the centred loss increments — nonnegative Lipschitz constant L, a diameter bound Rmax dominating every critical radius criticalRadius (ψ m), and the sub-root fixed-point property, plus boundedness and integrability of the empirical star-hull Rademacher process needed by the localization bridge and a confidence level in together with the Foster–Syrgkanis critical-radius domination inequality across dyadic shell counts. Then there is a nonnegative envelope b such that the DR-Learner system satisfies the localized empirical-process modulus predicate at rate ρ n = (8L+3)·criticalRadius (ψ |B(n)|) on nonempty validation folds, falling back to √(2b) when the fold is empty.
Formal statement
Proof (Lean source)
1 supporting declaration (lemmas, instances)
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localEmpProcessModulus_localized_drLearner_boundedtheorem — DR-Learner bounded-loss localized modulus.hypothesesIsFiniteMeasure P.μS :Θ :Θ_set :Set ΘΘ_convex :Convex ℝ Θ_setNonempty Θ_setθ₀ :Θθ₀_mem :θ₀ ∈ Θ_seteval :Θ → γ → ℝeval_meas :∀ θ, Measurable (eval θ)eval_θ₀ :∀ x, eval θ₀ x = S.τ_val xθ₀_minimizes :DRThetaMinimizes S Θ_set θ₀ evalsplit :OneShotSplit S_iidM_Θ M_Y M_μ ε :ℝhM_Θ :DREvalBounded Θ_set eval M_ΘhM_Y :DROutcomeBounded S M_Yh :hM_μ :DRNuisanceMuBounded h M_μhOverlap :DRNuisanceOverlap S Θ_set h ε_hLoss_cont :∀ z,Continuous fun (θ : (drLearningSystem S Θ Θ_set Θ_convex θ₀ θ₀_mem eval eval_meas eval_θ₀ θ₀_minimizes).Θ_set)=> (drLearningSystem S Θ Θ_set Θ_convex θ₀ θ₀_mem eval eval_meas eval_θ₀ θ₀_minimizes).ℓ z θ.val hidx :ℕ → (drLearningSystem S Θ Θ_set Θ_convex θ₀ θ₀_mem eval eval_meas eval_θ₀ θ₀_minimizes).Θ_set_idx_dense :DenseRange idxnorm :((γ × Bool × ℝ) → ℝ) → ℝψ :ℕ → ℝ → ℝhψ :DRCriticalRadius S Θ_set eval (fun k => ⟨((idx k).val), (idx k).property⟩) h norm ψδ :ℝhδ :0 < δhδ' :δ ≤ 1conclusion∃ b : ℝ,0 ≤ b ∧LocalEmpProcessModulus (drLearningSystem S Θ Θ_set Θ_convex θ₀ θ₀_mem eval eval_meas eval_θ₀ θ₀_minimizes) S_iid split (fun _n => sqrt (2 * (2 * b))) δ hProof (Lean source)
theorem localEmpProcessModulus_localized_drLearner_bounded [StandardBorelSpace P.Ω] [IsFiniteMeasure P.μ] [IsProbabilityMeasure P.μ] (S : CATEEstimationSystem P γ) (Θ : Type*) [NormedAddCommGroup Θ] [InnerProductSpace ℝ Θ] (Θ_set : Set Θ) (Θ_convex : Convex ℝ Θ_set) [Nonempty Θ_set] (θ₀ : Θ) (θ₀_mem : θ₀ ∈ Θ_set) (eval : Θ → γ → ℝ) (eval_meas : ∀ θ, Measurable (eval θ)) (eval_θ₀ : ∀ x, eval θ₀ x = S.τ_val x) (θ₀_minimizes : DRThetaMinimizes S Θ_set θ₀ eval) (S_iid : IIDSample P.Ω (γ × Bool × ℝ) P.μ S.toBackdoorEstimationSystem.P_Z) (split : OneShotSplit S_iid) {M_Θ M_Y M_μ ε : ℝ} (hM_Θ : DREvalBounded Θ_set eval M_Θ) (hM_Y : DROutcomeBounded S M_Y) (h : NuisanceVec γ) (hM_μ : DRNuisanceMuBounded h M_μ) (hOverlap : DRNuisanceOverlap S Θ_set h ε) (_hLoss_cont : ∀ z, Continuous fun (θ : (drLearningSystem S Θ Θ_set Θ_convex θ₀ θ₀_mem eval eval_meas eval_θ₀ θ₀_minimizes).Θ_set) => (drLearningSystem S Θ Θ_set Θ_convex θ₀ θ₀_mem eval eval_meas eval_θ₀ θ₀_minimizes).ℓ z θ.val h) (idx : ℕ → (drLearningSystem S Θ Θ_set Θ_convex θ₀ θ₀_mem eval eval_meas eval_θ₀ θ₀_minimizes).Θ_set) (_idx_dense : DenseRange idx) {norm : ((γ × Bool × ℝ) → ℝ) → ℝ} {ψ : ℕ → ℝ → ℝ} (hψ : DRCriticalRadius S Θ_set eval (fun k => ⟨((idx k).val), (idx k).property⟩) h norm ψ) {δ : ℝ} (hδ : 0 < δ) (hδ' : δ ≤ 1) : ∃ b : ℝ, 0 ≤ b ∧ LocalEmpProcessModulus (drLearningSystem S Θ Θ_set Θ_convex θ₀ θ₀_mem eval eval_meas eval_θ₀ θ₀_minimizes) S_iid split (fun _n => sqrt (2 * (2 * b))) δ h := by classical let Ssys := drLearningSystem S Θ Θ_set Θ_convex θ₀ θ₀_mem eval eval_meas eval_θ₀ θ₀_minimizes -- Nonempty instance for the system's parameter set. haveI : Nonempty Ssys.Θ_set := inferInstanceAs (Nonempty Θ_set) -- Probability-measure instance for P_Z (used by populationRisk integrability). haveI hPZ : IsProbabilityMeasure S.toBackdoorEstimationSystem.P_Z := by rw [← S_iid.law] exact Measure.isProbabilityMeasure_map (S_iid.meas 0).aemeasurable -- Step 1: extract uniform loss bound `b`. set b : ℝ := (M_Θ + 2 * M_μ + 2 * (M_Y + M_μ) / ε) ^ 2 with hb_def have hb_nonneg : 0 ≤ b := sq_nonneg _ have hb_loss : UniformlyBoundedLossAE Ssys h b := dr_loss_uniformly_bounded S Θ Θ_set Θ_convex θ₀ θ₀_mem eval eval_meas eval_θ₀ θ₀_minimizes hM_Θ hM_Y h hM_μ hOverlap refine ⟨b, hb_nonneg, ?_⟩ -- Step 2: derive the centred a.e. bound (factor 2). have h_centred_ae : ∀ᵐ z ∂S.toBackdoorEstimationSystem.P_Z, ∀ θ ∈ Ssys.Θ_set, |Ssys.ℓ z θ h - Ssys.ℓ z Ssys.θ₀ h| ≤ 2 * b := by filter_upwards [hb_loss] with z hz intro θ hθ have h1 : |Ssys.ℓ z θ h| ≤ b := hz θ hθ have h2 : |Ssys.ℓ z Ssys.θ₀ h| ≤ b := hz Ssys.θ₀ Ssys.θ₀_mem have htri := abs_sub (Ssys.ℓ z θ h) (Ssys.ℓ z Ssys.θ₀ h) linarith -- Step 3: derive the centred population bound via integration. have h_centred_pop : ∀ θ ∈ Ssys.Θ_set, |Ssys.L θ h - Ssys.L Ssys.θ₀ h| ≤ 2 * b := by intro θ hθ have hint_θ : Integrable (fun z => Ssys.ℓ z θ h) S.toBackdoorEstimationSystem.P_Z := Integrable.of_bound (Ssys.ℓ_meas θ h).aestronglyMeasurable b (by filter_upwards [hb_loss] with z hz simpa [Real.norm_eq_abs] using hz θ hθ) have hint_0 : Integrable (fun z => Ssys.ℓ z Ssys.θ₀ h) S.toBackdoorEstimationSystem.P_Z := Integrable.of_bound (Ssys.ℓ_meas Ssys.θ₀ h).aestronglyMeasurable b (by filter_upwards [hb_loss] with z hz simpa [Real.norm_eq_abs] using hz Ssys.θ₀ Ssys.θ₀_mem) have hL_eq : Ssys.L θ h - Ssys.L Ssys.θ₀ h = ∫ z, Ssys.ℓ z θ h - Ssys.ℓ z Ssys.θ₀ h ∂S.toBackdoorEstimationSystem.P_Z := by change (∫ z, Ssys.ℓ z θ h ∂S.toBackdoorEstimationSystem.P_Z) - (∫ z, Ssys.ℓ z Ssys.θ₀ h ∂S.toBackdoorEstimationSystem.P_Z) = _ rw [← integral_sub hint_θ hint_0] rw [hL_eq] calc |∫ z, Ssys.ℓ z θ h - Ssys.ℓ z Ssys.θ₀ h ∂S.toBackdoorEstimationSystem.P_Z| ≤ ∫ z, |Ssys.ℓ z θ h - Ssys.ℓ z Ssys.θ₀ h| ∂S.toBackdoorEstimationSystem.P_Z := abs_integral_le_integral_abs _ ≤ ∫ _z, 2 * b ∂S.toBackdoorEstimationSystem.P_Z := by apply integral_mono_ae · exact (hint_θ.sub hint_0).abs · exact integrable_const _ · filter_upwards [h_centred_ae] with z hz exact hz θ hθ _ = 2 * b := by simp -- Step 4: package the LocalizedRademacherRegime for Ssys. have hloss_eq : (fun (k : ℕ) (z : γ × Bool × ℝ) => Ssys.ℓ z (idx k).val h - Ssys.ℓ z Ssys.θ₀ h) = fun (k : ℕ) (z : γ × Bool × ℝ) => (phi_eta z h - eval (idx k).val z.1) ^ 2 - (phi_eta z h - S.τ_val z.1) ^ 2 := by funext k z change (phi_eta z h - eval (idx k).val z.1) ^ 2 - (phi_eta z h - eval θ₀ z.1) ^ 2 = (phi_eta z h - eval (idx k).val z.1) ^ 2 - (phi_eta z h - S.τ_val z.1) ^ 2 rw [eval_θ₀ z.1] have hreg : LocalizedRademacherRegimeAE Ssys S_iid split h idx norm ψ (2 * b) := by refine ⟨by linarith, h_centred_ae, hψ.1, ?_⟩ intro n have hub := hψ.2 (split.foldB n).card rw [hloss_eq] exact hub -- Step 5: apply the bounded fallback bridge. exact localEmpProcessModulus_of_localized_bounded_ae (S := Ssys) (S_iid := S_iid) (split := split) (g := h) (idx := idx) (norm := norm) (ψ := ψ) (b := 2 * b) (hreg := hreg) (hpop_center := h_centred_pop) (_hδ := hδ) (_hδ' := hδ')
DRLearnerEndToEnd 1 core · 0 supporting This file composes the generic plug-in oracle inequality with the global Rademacher modulus for the doubly robust learner for conditional treatment effects. ★ oracle_inequality_drLearner_highProb
DR-Learner Oracle Chain
This file composes the generic plug-in oracle inequality with the global Rademacher modulus for the doubly robust learner for conditional treatment effects. It yields a high-probability squared-error bound whose leading term is the empirical-process modulus and whose remaining terms are nuisance bias and optimization slack.
DR-Learner end-to-end high-probability oracle inequality. Consider the same doubly robust orthogonal-learning system, one-shot sample split, and boundedness / overlap / continuity / Rademacher package as in localEmpProcessModulus_drLearner — truth-identifying admissibility and evaluation correctness, uniform bounds on the candidate evaluations, the outcome, and the realised nuisance regression together with propensity overlap, and loss continuity, a Rademacher bound R n, the clamped-loss minimizer property, and a confidence level δ in (0, 1] . Assume in addition that a plug-in empirical-risk-minimisation estimator sequence τhat, evaluated against the same realised nuisance on every cross-fitting fold, attains the empirical risk up to an optimization slack r_opt n, that the population risk is strongly convex at the realised nuisance with modulus σ > 0, and that the truth-identifying candidate satisfies the first-order optimality inequality for the population risk's directional derivative at the truth. Then there is a nonnegative constant b such that, for every sample size n, with P.μ-probability at least 1 − δ the estimation error obeys ‖τhat n ω − θ₀‖² ≤ (4(1+σ)/σ²) · ρ_{n,δ}² + (4/σ) · Bias_n + (4/σ) · r_opt n, where ρ_{n,δ} is the modulus rate realised by localEmpProcessModulus_drLearner.
Formal statement
Proof (Lean source)
DRLearnerHonest 1 core · 0 supporting This file combines the doubly robust learner oracle inequality with the second-order product-bias bound. ★ oracle_inequality_drLearner_highProb_honest
Product-Bias DR-Learner Oracle Bound
This file combines the doubly robust learner oracle inequality with the
second-order product-bias bound. The resulting high-probability statement makes
the error contribution from the two nuisance estimators explicit as a product
of their conditional mean and propensity-score errors. The main theorem is
oracle_inequality_drLearner_highProb_honest; the declaration keeps the
historical suffix _honest, where "honest" means that the bound exposes the
second-order product term instead of leaving it as the symbolic Bias_n.
Product-bias DR-Learner oracle inequality. Consider a CATE estimation system satisfying the underlying backdoor identification assumptions, with an evaluation functional that is measurable in its parameter and recovers the true CATE at a parameter θ₀ belonging to the constraint set, and suppose the evaluation functional, the outcome, and a fixed plug-in nuisance's conditional-mean function are uniformly bounded while that nuisance's propensity score satisfies ε-overlap. Assume further the DR-loss is continuous in the parameter, its localized empirical process admits a Rademacher complexity bound, and a clamped version of θ₀ still minimizes the loss, the confidence level lies in , the overlap parameter is positive, and both the true and the plug-in nuisance lie in the ε-overlap slice, and that the estimator sequence stays within the constraint set as an approximate sample-split plug-in empirical-risk minimizer (slack r_opt) whose excess population risk satisfies a strong-convexity-type lower bound with constant σ>0 and a first-order orthogonality inequality at the true nuisance's directional derivative. Finally, a battery of boundedness and integrability conditions bounds the directional-derivative envelope and controls the two nuisance-error terms entering the second-order bias decomposition. Then for every sample fold n, with probability at least 1-δ the squared estimation error of the DR-Learner is bounded by an oracle/Rademacher term plus an explicit second-order product-bias term (2B/ε)·Σ_a ‖Δμ_a‖₂·‖Δe‖₂ in the two nuisance L²-errors, plus an optimization slack.
Formal statement
Proof (Lean source)
DRLearnerRandomNuisance 1 core · 0 supporting This file extends the doubly robust learner oracle inequality from a fixed nuisance value to a cross-fitted random nuisance estimate. ★ oracle_inequality_drLearner_random_nuisance
Random-Nuisance DR-Learner Bound
This file extends the doubly robust learner oracle inequality from a fixed
nuisance value to a cross-fitted random nuisance estimate. The resulting bound
keeps the empirical-process control as an event and evaluates the second-order
bias at the realized nuisance estimate. The main theorem
oracle_inequality_drLearner_random_nuisance combines the deterministic
plug-in ERM oracle inequality with the product-bias bound applied pointwise to
the realized nuisance.
DR-Learner oracle inequality at a random cross-fitted nuisance. Consider a CATE estimation system satisfying the backdoor identification assumptions, with an evaluation functional measurable in its parameter and recovering the true CATE at a parameter θ₀ in the constraint set, and suppose the overlap parameter is positive while the true nuisance and every realization of the random, fold-A-estimated nuisance ĥ n ω lie in the ε-overlap slice. Assume the estimator sequence stays in the constraint set as an approximate sample-split plug-in empirical-risk minimizer with respect to the random nuisance (slack r_opt), whose excess population risk at each realized ĥ n ω obeys a strong-convexity-type lower bound with constant σ>0, together with a first-order orthogonality inequality at the true nuisance's directional derivative, and that on a high-probability event the centred excess empirical risk at the realized estimator and nuisance is controlled by a rate ρ n. Finally, a battery of boundedness and integrability conditions governs the directional-derivative envelope and bounds the two random nuisance-error terms. Then for every n, with probability at least 1-δ the squared estimation error is bounded by the oracle/Rademacher term (4(1+σ)/σ²)·(ρ n)² plus a random second-order product-bias term (4/σ)·(2B/ε)·Σ_a ‖(ĥ n ω).μ_fn a − μ_val a‖₂·‖(ĥ n ω).e_fn − e_val‖₂ evaluated at the realized nuisance, plus an optimization slack (4/σ)·r_opt n.
Formal statement
Proof (Lean source)
LocalizedDRLearnerEndToEnd 1 core · 0 supporting This file composes the localized empirical-process modulus for the DR-Learner with the generic orthogonal statistical learning oracle inequality. ★ oracle_inequality_localized_drLearner_highProb
Localized DR-Learner Oracle Chain
This file composes the localized empirical-process modulus for the DR-Learner with the generic orthogonal statistical learning oracle inequality. It provides the high-probability CATE bound whose rate is governed by the localized critical radius, with a separate bounded branch for an empty validation fold.
DR-Learner localized high-probability oracle inequality. For the DR-Learner CATE estimation system, suppose the evaluation functional is measurable in its parameter and recovers the true CATE at a parameter θ₀ in the constraint set, and that the evaluation functional, outcome, and fixed nuisance conditional-mean are uniformly bounded while the nuisance's propensity score satisfies ε-overlap. Assume the centred DR-loss is continuous in θ, a clamped version of θ₀ minimizes it, its population Rademacher complexity along a dense index sequence is controlled by a sub-root envelope ψ with respect to a seminorm invariant under almost-everywhere modification, and the same Rademacher upper bound extends to loss differences across the whole constraint set, together with Lipschitz and diameter control of the centred loss increments — nonnegative Lipschitz constant L, a diameter bound Rmax dominating every critical radius, and the sub-root fixed-point property, plus boundedness and integrability of the empirical star-hull Rademacher process needed by the localization bridge and a confidence level in together with the Foster–Syrgkanis critical-radius domination inequality across dyadic shell counts. Finally, suppose the estimator sequence is an approximate sample-split plug-in empirical-risk minimizer at the fixed nuisance h (slack r_opt), whose excess population risk obeys a strong-convexity-type lower bound with constant σ>0, together with a first-order orthogonality inequality at the truth's directional derivative. Then there is a nonnegative envelope b such that, for every n, with probability at least 1-δ the squared estimation error is bounded by the oracle term (4(1+σ)/σ²)·(ρ n)² at the sharp localized Foster–Syrgkanis rate ρ n = (8L+3)·criticalRadius (ψ |B(n)|) (falling back to √(2b) on an empty validation fold), plus the nuisance bias term (4/σ)·Bias_n and an optimization slack (4/σ)·r_opt n.