Alphabeta Math
ExampleConstruction: AI-generatedVerification: AI-generatedPipeline-generatedjudge pass (gpt-6-luna)
How statement and proof provenance work

The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.

  • Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
  • AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
  • AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.

These labels describe origin, not correctness: citations and verification chips remain separate evidence.

Distant alternatives can prevent uniform testability

Example

On X={0,1} with counting measure, let p0(0)=p0(1)=1/2. Use labels 0,1,2,…, with p0 at label 0 and, for j≥1, pj(1)=1/2+δj,pj(0)=1/2−δj,δj:=1/(j+4). Give label 0 prior probability 1/2 and label j prior probability 2−(j+1). Use the discrete metric ρ(j,k)=0 if j=k and 1 otherwise, so every alternative is distance one from label 0. Take observations IID with the law at the selected parameter label.

Facts & Assumptions

Given: The model, prior, parameter metric, and IID law in the Example.

[F1]

KL projection sets and relative KL neighborhoods: the relative KL neighborhoods are defined using K(θ)−K∗.

[A1]

Assume AC through the imported KL convention The Axiom of Choice. The displayed finite density family is explicit.

[F2]

Total variation distance for probability laws: ∥P−Q∥TV=sup⁡A∣P(A)−Q(A)∣.

[F3]

Verification

1.1A1F1F3algebra

For δj=1/(j+4), direct substitution gives KL(P0∥Pj)=12log⁡1/21/2+δj+12log⁡1/21/2−δj=−12log⁡(1−4δj2)>0. Thus Θ∗={0}. Every relative KL neighborhood contains 0 and therefore has prior mass at least 1/2, while every j≥1 lies in the distance-one alternative set.

1.2F2givenalgebra

Fix n and choose jn≥n2. For one coordinate define a joint law of (X,Y) by masses 1/2−δjn at (0,0), 1/2 at (1,1), and δjn at (0,1), with zero mass at (1,0). Its marginals are P0 and Pjn, and its disagreement probability is δjn. Take the n-fold product of this finite joint law. By the union bound, the coupled vectors differ with probability at most nδjn≤1/n. For every event A, the indicators of {X1:n∈A} and {Y1:n∈A} can differ only when the vectors differ, so by [F2], ∥P0n−Pjnn∥TV≤1/n.

2.1F2step 1.2algebra∎

For probability laws P,Q on the finite set {0,1}n, ∥P−Q∥TV=∑z:P(z)>Q(z)(P(z)−Q(z)): the set of points with positive difference attains the supremum over events, and no event can sum more than all positive differences. Hence for every test ϕn with 0≤ϕn≤1, Pϕn−Qϕn=∑zϕn(z)(P(z)−Q(z))≤∑z:P(z)>Q(z)(P(z)−Q(z))=∥P−Q∥TV. Taking P=P0n, Q=Pjnn and rearranging gives P0nϕn+Pjnn(1−ϕn)≥1−∥P0n−Pjnn∥TV≥1−1n. If P0nϕn→0, then sup⁡j≥1Pjn(1−ϕn)≥Pjnn(1−ϕn)→1. Since the selected minimizer is the true law, Qj=Pj here. Thus no test sequence has both error limits required by the KL-projection theorem.

Depends on

Used by

Nothing in the library uses this result yet.

Dependency tree · two levels

15 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.

Sources