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NormalizedReferenceCall: mathematical reading route

Read the statements and derivations in source order. Every result has its own optional Lean statement and proof. Source assumptions, library reuse and unproved boundaries are kept explicit.

  1. Actual normalized reference and returned sampling precision
ASTIS mathematical exposition

Actual normalized reference and returned sampling precision

AutoSamplingTheory.ExampleCases.SmoothedPicardHMC.NormalizedReferenceCall.normalized_reference_call · theorem · Teaching coverage

Statement

N and p->S(out(p)) are measurable. For every p, the actual output satisfies norm(grad F_p(out))^2<=a*d and every earlier iterate strictly fails that threshold. The scaled reference satisfies norm(grad G_p(S(out)))^2<=d/k. G_p is C2 with genuine Hessian bounds [a/c,1]. Both exponential Gibbs weights are integrable with strictly positive integrals, and both tilted laws are probability measures. S#pi_p=pibar_p and grad G_p(S(x))=c^(-1/2)*grad F_p(x). For every next variance t>=0, R#H(pibar_p,sqrt(t))=H(pi_p,sqrt(t/c)). For every actual probability nubar and t,B>=0, a supplied W2(nubar,H(pibar_p,sqrt(t)))^2<=ofReal(B) implies W2(R#nubar,H(pi_p,sqrt(t/c)))^2<=ofReal(B/c).

\[\|\nabla G_p(S\,\mathrm{out}(p))\|^2\le d/k,\quad S_\#\pi_p=\bar\pi_p,\quad R_\#H(\bar\pi_p,\sqrt t)=H(\pi_p,\sqrt{t/c}),\quad W_2^2\le B/c.\]

All objects and hypotheses

  • E is a complete finite-dimensional real inner-product space with its Borel measurable structure and canonical volume; d=dim(E)>0. U is C2 and its genuine Hessian lies between alpha*norm(v)^2 and beta*norm(v)^2 for every x,v, with 0<alpha<=beta.
  • eta>=0,tau>0,r>=0. The actual probability nu satisfies W2(nu,law(X+sqrt(eta)*Z))^2<=ofReal(r^2), where X has the normalized Gibbs law volume.tilted(-U) and Z is an independent standard Gaussian. This is the outer input to the existing actual reference construction.
  • A=eta+tau,a=alpha+1/A,c=beta+1/A,k=c/a. For p=(y,z), u(p)=y+sqrt(tau)*z and F_p(x)=U(x)+norm(x-u(p))^2/(2*A). Here a is a curvature lower bound, not an RGO variance.
  • T_p(x)=x-c^(-1)*grad F_p(x). N(p) is the least n with norm(grad F_p(T_p^n(y)))^2<=a*d if such an n exists, otherwise zero; out(p)=T_p^N(p)(y). The inherited finite-hit proof eliminates the default branch.
  • S(x)=sqrt(c)*x,R(x)=x/sqrt(c),G_p(x)=F_p(R(x)). pi_p=volume.tilted(-F_p) and pibar_p=volume.tilted(-G_p). Write H(mu,sigma)=law(X+sigma*Z) for independent X~mu,Z~stdGaussian(E). W2 squared is the extended nonnegative infimum of quadratic coupling costs.

Mathematical proof

1. Retain the actual first-hit program and pair dependence

The parent JointReferenceGradientDescent theorem is applied to the same U,eta,tau and actual outer input law. actualIndex is definitionally the same first ad-hit program. Thus N and out are measurable, the stopped gradient satisfies the threshold, and every earlier iterate fails it. Continuous S preserves output measurability. No supplied reference point replaces the program.

\[N(p)=\min\{n:\|\nabla F_p(T_p^n(p_1))\|^2\le ad\},\qquad p\mapsto S(\mathrm{out}(p))\text{ is measurable}.\]
Corresponding Lean step

actualIndex; normalized_reference_call: hP,hNm,hom,hp,hearly

2. Differentiate the actual regularized potential

Differentiate the quadratic norm term twice. Its first derivative is A^(-1) inner(x-u,.) and its second derivative is A^(-1) inner(.,.). Adding these genuine derivatives to those of U shifts both Hessian bounds by A^(-1); no independent Hessian field is assumed.

\[D^2F_p(x)[v,v]=D^2U(x)[v,v]+A^{-1}\|v\|^2,\qquad a\|v\|^2\le D^2F_p(x)[v,v]\le c\|v\|^2.\]
Corresponding Lean step

regularized_hessian: hq,hfd,hdd; normalized_reference_call: hreg,hFH

3. Apply the chain rule and certify the scaled reference

For any real scalar s, differentiating F(s*x) gives s times its gradient and s^2 times its Hessian quadratic form. Set s=1/sqrt(c), using c>0. The actual stopped threshold ad becomes ad/c=d/k. The same chain rule gives normalized curvature [a/c,1].

\[\nabla G_p(Sx)=c^{-1/2}\nabla F_p(x),\quad D^2G_p(x)[v,v]=c^{-1}D^2F_p(Rx)[v,v],\quad ad/c=d/k.\]
Corresponding Lean step

differential_scaling; normalized_laws: hD,hGH; normalized_reference_call: hi,hb

4. Prove both Gibbs normalizations before identifying probability laws

Positive Hessian lower bounds imply strong convexity of F and G. StrongConvexGibbsIntegrability supplies integrability of their actual exponential weights without a minimizer assumption. Positive exponential integrals then give nonzero finite normalizers and actual probability tilted measures.

\[0<Z_F=\int e^{-F(x)}\,dx<\infty,\qquad 0<Z_G=\int e^{-G(x)}\,dx<\infty.\]
Corresponding Lean step

normalized_laws: hI,hIG; HessianStrongConvexity.strongConvexOn_univ_of_fderiv2_lower; integral_exp_pos; isProbabilityMeasure_tilted

5. Cancel the same volume Jacobian in numerator and denominator

For s=sqrt(c)>0, the volume substitution has J=abs((s^d)^(-1))>0. On each measurable B it gives I_F(S^(-1)B)=J*I_G(B), and also Z_F=J*Z_G. The tilted setwise formula cancels J, proving S#pi_F=pi_G. The private identity also supports total-integral degenerate inputs; the actual public consumer separately proves true positive normalization.

\[(S_\#\pi_F)(B)=\frac{J\int_B e^{-G(x)}dx}{JZ_G}=\pi_G(B),\qquad J=c^{-d/2}.\]
Corresponding Lean step

scaled_gibbs: hJ,hZ,hI; Measure.integral_comp_smul; tilted_apply_eq_ofReal_integral'

6. Transform the actual independent Gaussian product law

Expand H(mu,sigma) as the pushforward of mu.prod(stdGaussian) by (x,z)->x+sigma*z. Product-map and map-composition identities show R(SX+sqrt(t)Z)=X+sqrt(t/c)Z. The next t is distinct from the current eta and tau; t=0 is included.

\[R_\#H(S_\#\pi,\sqrt t)=H(\pi,c^{-1/2}\sqrt t)=H(\pi,\sqrt{t/c}).\]
Corresponding Lean step

scaled_smoothing: law,hp; normalized_laws: hsm; Measure.map_prod_map; Measure.map_map; Real.sqrt_div

7. Push each coupling and take the cost infimum

For any coupling gamma, map the pair by (x,y)->(s*x,s*y). Its two marginals are exactly the scaled marginals, and its quadratic cost is s^2 times the original cost. Since ofReal(s^2) is positive and finite for nonzero s, it commutes with both indexed infima defining transport cost, even for infinite cost or an empty coupling set. No optimal coupling or separate second-moment assumption is used.

\[\int\|sx-sy\|^2d\gamma=s^2\int\|x-y\|^2d\gamma,\quad W_2^2(s_\#\mu,s_\#\nu)\le s^2W_2^2(\mu,\nu).\]
Corresponding Lean step

scaled_wasserstein: hcouple,hcost; ENNReal.mul_iInf_of_ne; Transport.transportCost_le_lintegral_of_isCoupling

8. Propagate the supplied next-call precision

Apply the coupling bound with s=1/sqrt(c), substitute the proved smoothing-law identity, and use the nonnegative supplied budget B. This yields actual returned squared precision B/c. The source choice B=k*epsilon^2 therefore returns epsilon^2/a. This step consumes the normalized sampler guarantee; constructing that sampler and propagating conditional histories and total costs remain separate.

\[W_2^2(\bar\nu,H(\bar\pi,\sqrt t))\le B\Longrightarrow W_2^2(R_\#\bar\nu,H(\pi,\sqrt{t/c}))\le B/c;\quad \frac{k\varepsilon^2}{c}=\frac{\varepsilon^2}{a}.\]
Corresponding Lean step

normalized_laws: hprec; normalized_reference_call: hprec

Lean statement · normalized_reference_call

Actual first-hit reference normalization,genuine Hessian,positive Gibbs laws,Gaussian variance and returned Wasserstein precision.

Braces mark parameters Lean can infer; square brackets request structures such as a measurable space or probability measure. Named hypotheses are mathematical premises, not facts established by this declaration. Section parameters are described in the mathematical hypotheses above; the module link retains their exact source context.

theorem normalized_reference_call [FiniteDimensional ℝ E]
    [MeasurableSpace E] [BorelSpace E] {U : E → ℝ} {α β : ℝ≥0}
    (hα : 0 < α) (hαβ : α ≤ β) (hU : ContDiff ℝ 2 U)
    (hH : ∀ x v : E, (α:ℝ)*‖v‖^2 ≤ fderiv ℝ (fderiv ℝ U) x v v ∧
      fderiv ℝ (fderiv ℝ U) x v v ≤ (β:ℝ)*‖v‖^2)
    {η τ r : ℝ} (hη : 0 ≤ η) (hτ : 0 < τ) (hr : 0 ≤ r)
    (hd : 0 < (Module.finrank ℝ E : ℝ))
    (ν : Measure E) [IsProbabilityMeasure ν]
    (hw : TechnicalLemmas.Measure.WassersteinSpace.wassersteinDistance ν
      (TechnicalLemmas.Measure.GaussianSmoothing.gaussianSmoothing
        ((volume : Measure E).tilted (fun x => -U x)) (Real.sqrt η)) ^ 2 ≤ ENNReal.ofReal (r^2)) :
    let d : ℝ := Module.finrank ℝ E
    let A := η+τ
    let a := (α:ℝ)+A⁻¹
    let c := (β:ℝ)+A⁻¹
    let k := c/a
    let u := fun p : E × E => p.1+Real.sqrt τ • p.2
    let F := fun p x => U x+A⁻¹/2*‖x-u p‖^2
    let T := fun p x => x-c⁻¹ • gradient (F p) x
    let N := actualIndex T (fun p x => ‖gradient (F p) x‖^2) (a*d)
    let out := fun p => (T p)^[N p] p.1
    let S := fun x : E => Real.sqrt c • x
    let R := fun x : E => (Real.sqrt c)⁻¹ • x
    let G := fun p x => F p (R x)
    let π := fun p => (volume : Measure E).tilted (fun x => -F p x)
    let πbar := fun p => (volume : Measure E).tilted (fun x => -G p x)
    Measurable N ∧ Measurable (fun p => S (out p)) ∧
    (∀ p, ‖gradient (F p) (out p)‖^2 ≤ a*d ∧
      (∀ j < N p, a*d < ‖gradient (F p) ((T p)^[j] p.1)‖^2) ∧
      ‖gradient (G p) (S (out p))‖^2 ≤ d/k ∧
      ContDiff ℝ 2 (G p) ∧
      (∀ x v, (a/c)*‖v‖^2 ≤ fderiv ℝ (fderiv ℝ (G p)) x v v ∧
        fderiv ℝ (fderiv ℝ (G p)) x v v ≤ ‖v‖^2) ∧
      Integrable (fun x => Real.exp (-F p x)) (volume : Measure E) ∧
      0 < ∫ x : E, Real.exp (-F p x) ∧ IsProbabilityMeasure (π p) ∧
      Integrable (fun x => Real.exp (-G p x)) (volume : Measure E) ∧
      0 < ∫ x : E, Real.exp (-G p x) ∧ IsProbabilityMeasure (πbar p) ∧
      (π p).map S = πbar p ∧
      (∀ x, gradient (G p) (S x) = (Real.sqrt c)⁻¹ • gradient (F p) x) ∧
      (∀ t : ℝ, 0 ≤ t →
        (TechnicalLemmas.Measure.GaussianSmoothing.gaussianSmoothing (πbar p) (Real.sqrt t)).map R =
          TechnicalLemmas.Measure.GaussianSmoothing.gaussianSmoothing (π p) (Real.sqrt (t/c))) ∧
      (∀ (νbar : Measure E) (t B : ℝ), IsProbabilityMeasure νbar → 0 ≤ t → 0 ≤ B →
        TechnicalLemmas.Measure.WassersteinSpace.wassersteinDistance νbar
          (TechnicalLemmas.Measure.GaussianSmoothing.gaussianSmoothing (πbar p) (Real.sqrt t)) ^ 2 ≤
            ENNReal.ofReal B →
        TechnicalLemmas.Measure.WassersteinSpace.wassersteinDistance (νbar.map R)
          (TechnicalLemmas.Measure.GaussianSmoothing.gaussianSmoothing (π p) (Real.sqrt (t/c))) ^ 2 ≤
            ENNReal.ofReal (B/c)))

Exact module and namespace context

Lean proof · normalized_reference_call

Chain rules,actual first-hit parent,positive strong-convex Gibbs normalization,Haar substitution,product maps,and arbitrary-coupling infimum scaling.

Braces mark parameters Lean can infer; square brackets request structures such as a measurable space or probability measure. Named hypotheses are mathematical premises, not facts established by this declaration. Section parameters are described in the mathematical hypotheses above; the module link retains their exact source context.

theorem normalized_reference_call [FiniteDimensional ℝ E]
    [MeasurableSpace E] [BorelSpace E] {U : E → ℝ} {α β : ℝ≥0}
    (hα : 0 < α) (hαβ : α ≤ β) (hU : ContDiff ℝ 2 U)
    (hH : ∀ x v : E, (α:ℝ)*‖v‖^2 ≤ fderiv ℝ (fderiv ℝ U) x v v ∧
      fderiv ℝ (fderiv ℝ U) x v v ≤ (β:ℝ)*‖v‖^2)
    {η τ r : ℝ} (hη : 0 ≤ η) (hτ : 0 < τ) (hr : 0 ≤ r)
    (hd : 0 < (Module.finrank ℝ E : ℝ))
    (ν : Measure E) [IsProbabilityMeasure ν]
    (hw : TechnicalLemmas.Measure.WassersteinSpace.wassersteinDistance ν
      (TechnicalLemmas.Measure.GaussianSmoothing.gaussianSmoothing
        ((volume : Measure E).tilted (fun x => -U x)) (Real.sqrt η)) ^ 2 ≤ ENNReal.ofReal (r^2)) :
    let d : ℝ := Module.finrank ℝ E
    let A := η+τ
    let a := (α:ℝ)+A⁻¹
    let c := (β:ℝ)+A⁻¹
    let k := c/a
    let u := fun p : E × E => p.1+Real.sqrt τ • p.2
    let F := fun p x => U x+A⁻¹/2*‖x-u p‖^2
    let T := fun p x => x-c⁻¹ • gradient (F p) x
    let N := actualIndex T (fun p x => ‖gradient (F p) x‖^2) (a*d)
    let out := fun p => (T p)^[N p] p.1
    let S := fun x : E => Real.sqrt c • x
    let R := fun x : E => (Real.sqrt c)⁻¹ • x
    let G := fun p x => F p (R x)
    let π := fun p => (volume : Measure E).tilted (fun x => -F p x)
    let πbar := fun p => (volume : Measure E).tilted (fun x => -G p x)
    Measurable N ∧ Measurable (fun p => S (out p)) ∧
    (∀ p, ‖gradient (F p) (out p)‖^2 ≤ a*d ∧
      (∀ j < N p, a*d < ‖gradient (F p) ((T p)^[j] p.1)‖^2) ∧
      ‖gradient (G p) (S (out p))‖^2 ≤ d/k ∧
      ContDiff ℝ 2 (G p) ∧
      (∀ x v, (a/c)*‖v‖^2 ≤ fderiv ℝ (fderiv ℝ (G p)) x v v ∧
        fderiv ℝ (fderiv ℝ (G p)) x v v ≤ ‖v‖^2) ∧
      Integrable (fun x => Real.exp (-F p x)) (volume : Measure E) ∧
      0 < ∫ x : E, Real.exp (-F p x) ∧ IsProbabilityMeasure (π p) ∧
      Integrable (fun x => Real.exp (-G p x)) (volume : Measure E) ∧
      0 < ∫ x : E, Real.exp (-G p x) ∧ IsProbabilityMeasure (πbar p) ∧
      (π p).map S = πbar p ∧
      (∀ x, gradient (G p) (S x) = (Real.sqrt c)⁻¹ • gradient (F p) x) ∧
      (∀ t : ℝ, 0 ≤ t →
        (TechnicalLemmas.Measure.GaussianSmoothing.gaussianSmoothing (πbar p) (Real.sqrt t)).map R =
          TechnicalLemmas.Measure.GaussianSmoothing.gaussianSmoothing (π p) (Real.sqrt (t/c))) ∧
      (∀ (νbar : Measure E) (t B : ℝ), IsProbabilityMeasure νbar → 0 ≤ t → 0 ≤ B →
        TechnicalLemmas.Measure.WassersteinSpace.wassersteinDistance νbar
          (TechnicalLemmas.Measure.GaussianSmoothing.gaussianSmoothing (πbar p) (Real.sqrt t)) ^ 2 ≤
            ENNReal.ofReal B →
        TechnicalLemmas.Measure.WassersteinSpace.wassersteinDistance (νbar.map R)
          (TechnicalLemmas.Measure.GaussianSmoothing.gaussianSmoothing (π p) (Real.sqrt (t/c))) ^ 2 ≤
            ENNReal.ofReal (B/c))) := by
  let d : ℝ := Module.finrank ℝ E
  let A := η+τ
  let a := (α:ℝ)+A⁻¹
  let c := (β:ℝ)+A⁻¹
  let k := c/a
  let u := fun p : E × E => p.1+Real.sqrt τ • p.2
  let F := fun p x => U x+A⁻¹/2*‖x-u p‖^2
  let T := fun p x => x-c⁻¹ • gradient (F p) x
  let N := actualIndex T (fun p x => ‖gradient (F p) x‖^2) (a*d)
  let out := fun p => (T p)^[N p] p.1
  let S := fun x : E => Real.sqrt c • x
  let R := fun x : E => (Real.sqrt c)⁻¹ • x
  let G := fun p x => F p (R x)
  have hA : 0 < A := add_pos_of_nonneg_of_pos hη hτ
  have ha : 0 < a := add_pos_of_nonneg_of_pos α.coe_nonneg (inv_pos.mpr hA)
  have hc : 0 < c := add_pos_of_nonneg_of_pos β.coe_nonneg (inv_pos.mpr hA)
  have hs : 0 < Real.sqrt c := Real.sqrt_pos.mpr hc
  have hi : (Real.sqrt c)⁻¹^2=c⁻¹ := by rw [inv_pow,Real.sq_sqrt hc.le]
  have hP := JointReferenceGradientDescent.joint_reference_gradient_descent
    hα hαβ hU hH hη hτ hr hd ν hw
  have hNm : Measurable N := hP.1
  have hom : Measurable out := hP.2.1
  refine ⟨hNm,(by fun_prop : Measurable S).comp hom,fun p => ?_⟩
  have hreg := regularized_hessian hU A⁻¹ (u p)
  have hFH (x v : E) : a*‖v‖^2 ≤ fderiv ℝ (fderiv ℝ (F p)) x v v ∧
      fderiv ℝ (fderiv ℝ (F p)) x v v ≤ c*‖v‖^2 := by
    rw [hreg.2]
    dsimp [a,c]
    constructor <;> nlinarith [(hH x v).1,(hH x v).2]
  obtain ⟨hG,hGH,hI,hZ,hprob,hIG,hZG,hprobG,hmap,hgrad,hsm,hprec⟩ :=
    normalized_laws ha hc hreg.1 hFH
  have hp : ‖gradient (F p) (out p)‖^2 ≤ a*d := (hP.2.2.1 p).1
  have hearly : ∀ j < N p, a*d < ‖gradient (F p) ((T p)^[j] p.1)‖^2 :=
    (hP.2.2.1 p).2.2.2.1
  refine ⟨hp,hearly,?_,hG,hGH,hI,hZ,hprob,hIG,hZG,hprobG,hmap,hgrad,hsm,
    fun νbar t B _ ht _ hbudget => hprec νbar t B ht hbudget⟩
  rw [hgrad,norm_smul,Real.norm_eq_abs,mul_pow,sq_abs,hi]
  have hb := mul_le_mul_of_nonneg_left hp (inv_pos.mpr hc).le
  calc
    c⁻¹*‖gradient (F p) (out p)‖^2 ≤ c⁻¹*(a*d) := hb
    _ = d/k := by dsimp [k]; field_simp

end AutoSamplingTheory.ExampleCases.SmoothedPicardHMC.NormalizedReferenceCall

Exact module and namespace context

Scope and omitted-condition boundaries

  • Fixed-call normalization of the actual first ad-hit reference and actual sampling laws. General beta, coordinate-free finite dimension and eta=0,t=0,r=0,B=0 extend the source; d>0,tau>0,0<alpha<=beta remain required. The outer W2 input and next normalized output precision are distinct supplied guarantees. No sampler achieving the next budget, all-parameter kernel, measurable sampler selection, conditional history or stage costs are proved. The public transport conclusion is the needed inequality, not a full isometry theorem. For source B=k*epsilon^2, B/c=epsilon^2/a; a here denotes regularized curvature. Returned probability is a standard measurable-pushforward consequence, not an extra public conjunct. Both main results remain incomplete.

Source and reuse

ASTIS parents called

Mathlib API called (external library)

  • MeasureTheory.Measure.integral_comp_smul
  • MeasureTheory.tilted_apply_eq_ofReal_integral'
  • MeasureTheory.Measure.map_prod_map
  • MeasureTheory.Measure.map_map
  • ENNReal.mul_iInf_of_ne

Mathematical sources

  • SPHMC Sections6.1 and6.3 normalization convention and next call — Fixed-call normalization of the actual first ad-hit reference and actual sampling laws. General beta, coordinate-free finite dimension and eta=0,t=0,r=0,B=0 extend the source; d>0,tau>0,0<alpha<=beta remain required. The outer W2 input and next normalized output precision are distinct supplied guarantees. No sampler achieving the next budget, all-parameter kernel, measurable sampler selection, conditional history or stage costs are proved. The public transport conclusion is the needed inequality, not a full isometry theorem. For source B=k*epsilon^2, B/c=epsilon^2/a; a here denotes regularized curvature. Returned probability is a standard measurable-pushforward consequence, not an extra public conjunct. Both main results remain incomplete.

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