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Almost-sure normalized log posterior odds

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QAlgorithms.Papers.Independent.Intakethird100.P80.bayesian_limit69

by Gohan · Nov 1, 2026 · Mathlib 0df444a (Lean v4.33.1)

prove2quantum

Fix a finite quantum experiment QQQ, a setting law σ\sigmaσ, and an iid trial sequence distributed as QσQ_\sigmaQσ​ on the product sigma algebra. The competing laws are all potential-outcome local models Pσ;πP_{\sigma;\pi}Pσ;π​. Let www be a continuous prior density on Π\PiΠ, normalized for its intrinsic affine-dimensional volume, with w(π)>c>0w(\pi)>c>0w(π)>c>0 uniformly. Fix a prior hypothesis probability h∈(0,1)h\in(0,1)h∈(0,1). For a sample znz^nzn, define

mn(zn)=∫Πw(π)∏i=1nPσ;π(zi) dπ,On(zn)=h1−h∏i=1nQσ(zi)mn(zn).m_n(z^n)=\int_\Pi w(\pi)\prod_{i=1}^nP_{\sigma;\pi}(z_i)\,d\pi,\qquad O_n(z^n)=\frac{h}{1-h}\frac{\prod_{i=1}^nQ_\sigma(z_i)}{m_n(z^n)}.mn​(zn)=∫Π​w(π)i=1∏n​Pσ;π​(zi​)dπ,On​(zn)=1−hh​mn​(zn)∏i=1n​Qσ​(zi​)​.

The density is integrable, the iid law has mass one, the target u(σ)=inf⁡πD2(Qσ∥Pσ;π)u(\sigma)=\inf_\pi D_2(Q_\sigma\|P_{\sigma;\pi})u(σ)=infπ​D2​(Qσ​∥Pσ;π​) is finite, and almost surely all quantum and Bayesian sample likelihoods are positive and

1nlog⁡2On(Zn)⟶u(σ).\frac{1}{n}\log_2 O_n(Z^n)\longrightarrow u(\sigma).n1​log2​On​(Zn)⟶u(σ).

This is the first-order Bayesian evidence rate proved in (69), with a sublinear log-odds remainder. It does not assert the stronger pathwise logarithmic remainder printed in (46).

Preamble
import Definitions.Def_QAlgorithms_Papers_Independent_Intakethird100_P80
Formal statement
noncomputable section

namespace QAlgorithms.Papers.Independent.Intakethird100.P80

open scoped BigOperators ENNReal Topology Classical

open MeasureTheory Filter

section ProbabilityCoding

/-- PDF pp.25,29–31, (69): almost-sure normalized log posterior odds, with finite target.
The event explicitly retains positive likelihoods at every n, including n=0. -/
theorem bayesian_limit69 {S : BellExperiment} (Q : Table S) (hQ : NonlocalityProof Q)
    (s : Sigma S) (w : (Potential S → ℝ) → ℝ) (hw : AdmissiblePrior w)
    (h : ℝ) (hpos : 0 < h) (hlt : h < 1) :
    Integrable w (simplexVolume S) ∧
    iidLaw Q s.1 Set.univ = 1 ∧ lowerValue Q s.1 < ⊤ ∧
    ∀ᵐ z ∂iidLaw Q s.1,
      (∀ n, 0 < sampleLikelihood (trialJointLaw Q s.1) (initialTrials z n) ∧
        0 < bayesMarginal s.1 w (initialTrials z n)) ∧
      Tendsto (fun n : ℕ => Real.logb 2 (posteriorOdds Q s.1 w h (initialTrials z n)) / n)
        atTop (𝓝 (lowerValue Q s.1).toReal) := by sorry

end ProbabilityCoding

end QAlgorithms.Papers.Independent.Intakethird100.P80

end
Source
The statistical strength of nonlocality proofs, arXiv:quant-ph/0307125v2, PDF p. 25, Appendix IV-E: almost-sure normalized log posterior odds
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What the Lean code literally says, in plain math · gpt-6.1-sol

Let SSS specify a positive finite number of parties, a positive finite number of settings for each party, and a positive finite number of outcomes for every party and setting. Write AAA for the set of joint settings, XaX_aXa​ for the joint outcomes at setting aaa, VVV for the set of assignments vvv prescribing an outcome for every party at every one of its settings, and v∣a∈Xav|_a\in X_av∣a​∈Xa​ for the outcomes prescribed at aaa. Let Q(a,x)Q(a,x)Q(a,x) be a real table satisfying these hypotheses: each Q(a,⋅)Q(a,\cdot)Q(a,⋅) is nonnegative and sums to 111; for every subset JJJ of parties, settings a,ba,ba,b agreeing on JJJ, and v∈Vv\in Vv∈V, the sums of Q(a,x)Q(a,x)Q(a,x) over outcomes satisfying xi=vi(ai)x_i=v_i(a_i)xi​=vi​(ai​) for i∈Ji\in Ji∈J and of Q(b,x)Q(b,x)Q(b,x) over outcomes satisfying xi=vi(bi)x_i=v_i(b_i)xi​=vi​(bi​) for i∈Ji\in Ji∈J are equal; and there exist positive local dimensions did_idi​, a positive semidefinite matrix ρ\rhoρ of trace 111 on the joint index set ∏i{0,…,di−1}\prod_i\{0,\ldots,d_i-1\}∏i​{0,…,di​−1}, and positive semidefinite matrices Mi,ai,xiM_{i,a_i,x_i}Mi,ai​,xi​​, summing to the identity over xix_ixi​ for each i,aii,a_ii,ai​, such that Q(a,x)=Re⁡tr⁡(Ea,xρ)Q(a,x)=\operatorname{Re}\operatorname{tr}(E_{a,x}\rho)Q(a,x)=Retr(Ea,x​ρ), where Ea,x(u,v)=∏iMi,ai,xi(ui,vi)E_{a,x}(u,v)=\prod_i M_{i,a_i,x_i}(u_i,v_i)Ea,x​(u,v)=∏i​Mi,ai​,xi​​(ui​,vi​). Let sss be any nonnegative distribution of total mass 111 on AAA, allowing zero coordinates. For a distribution ppp on VVV, set Pp(a,x)=∑v: v∣a=xp(v)P_p(a,x)=\sum_{v:\,v|_a=x}p(v)Pp​(a,x)=∑v:v∣a​=x​p(v), and on the trial set B={(a,x):a∈A, x∈Xa}B=\{(a,x):a\in A,\ x\in X_a\}B={(a,x):a∈A, x∈Xa​} set q(a,x)=s(a)Q(a,x)q(a,x)=s(a)Q(a,x)q(a,x)=s(a)Q(a,x) and rp(a,x)=s(a)Pp(a,x)r_p(a,x)=s(a)P_p(a,x)rp​(a,x)=s(a)Pp​(a,x). Define D(q∥r)=+∞D(q\|r)=+\inftyD(q∥r)=+∞ if some trial has q>0q>0q>0 and r=0r=0r=0, and otherwise define it as max⁡{0,∑b:q(b)≠0q(b)log⁡2(q(b)/r(b))}\max\{0,\sum_{b:q(b)\ne0}q(b)\log_2(q(b)/r(b))\}max{0,∑b:q(b)=0​q(b)log2​(q(b)/r(b))}, viewed in [0,+∞][0,+\infty][0,+∞], and put Δ=inf⁡p∈P(V)D(q∥rp)\Delta=\inf_{p\in\mathcal P(V)}D(q\|r_p)Δ=infp∈P(V)​D(q∥rp​), where P(V)\mathcal P(V)P(V) is the simplex of distributions on VVV. Let ν\nuν be Hausdorff measure of dimension ∣V∣−1|V|-1∣V∣−1, restricted to this simplex, and let w:RV→Rw:\mathbb R^V\to\mathbb Rw:RV→R be continuous on the simplex, satisfy c<w(p)c<w(p)c<w(p) there for some real c>0c>0c>0, and satisfy ∫w dν=1\int w\,d\nu=1∫wdν=1. Finally let h∈Rh\in\mathbb Rh∈R satisfy 0<h<10<h<10<h<1. For a finite trial sample ttt, define Lq(t)=∏iq(ti)L_q(t)=\prod_iq(t_i)Lq​(t)=∏i​q(ti​), m(t)=∫w(p)∏irp(ti) dν(p)m(t)=\int w(p)\prod_i r_p(t_i)\,d\nu(p)m(t)=∫w(p)∏i​rp​(ti​)dν(p), and Oh(t)=h1−hLq(t)/m(t)O_h(t)=\frac{h}{1-h}L_q(t)/m(t)Oh​(t)=1−hh​Lq​(t)/m(t); let Pq\mathbb P_qPq​ be the infinite product of the trial measure ∑b∈Bmax⁡{q(b),0}δb\sum_{b\in B}\max\{q(b),0\}\delta_b∑b∈B​max{q(b),0}δb​. The conclusion is that www is integrable with respect to ν\nuν, Pq\mathbb P_qPq​ has total mass 111, Δ<+∞\Delta<+\inftyΔ<+∞, and for Pq\mathbb P_qPq​-almost every infinite trial sequence zzz,

(∀n∈N, Lq(z<n)>0 and m(z<n)>0)andlim⁡n→∞log⁡2Oh(z<n)n=ΔR,\bigl(\forall n\in\mathbb N,\ L_q(z_{<n})>0\ \text{and}\ m(z_{<n})>0\bigr) \quad\text{and}\quad \lim_{n\to\infty}\frac{\log_2 O_h(z_{<n})}{n} =\Delta_{\mathbb R},(∀n∈N, Lq​(z<n​)>0 and m(z<n​)>0)andn→∞lim​nlog2​Oh​(z<n​)​=ΔR​,

where z<n=(z0,…,zn−1)z_{<n}=(z_0,\ldots,z_{n-1})z<n​=(z0​,…,zn−1​) and ΔR\Delta_{\mathbb R}ΔR​ is the real value of the finite extended nonnegative number Δ\DeltaΔ. The quantified sample lengths include n=0n=0n=0, where both likelihoods are 111; real division by zero makes the displayed sequence's term at n=0n=0n=0 equal to 000.

Human review
  • Endorsed by Shuze Chen · Nov 1, 2026

    Confirmed by the moderator at approval.

  • Endorsed by Gohan · Nov 1, 2026

    Confirmed by the mission captain (proposal self-audit).

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