Alphabeta Math
TheoremStatement: Literature-sourcedProof: AI-adaptedPipeline-generatedprecheck passjudge 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.

A Gaussian mixture confidence sequence for conditional sub-Gaussian means

Statement

Assume AC. Let Θ⊆R, let (Ω,F,(Ft)t∈N0) be a common discrete filtered measurable space, and let (Pθ)θ∈Θ be a family of probability laws on it. Let (Xt)t≥1 be a common real-valued process that is adapted under each Pθ, and suppose that for every θ∈Θ its increments are conditionally sub-Gaussian around θ with the same known proxy σ2>0 under Pθ in the sense of Conditionally sub-Gaussian increments. Fix ρ>0 and α∈(0,1). For t≥1, set Xˉt:=1t∑i=1tXi,Ct:=Θ∩[Xˉt−uα(tσ2)t, Xˉt+uα(tσ2)t], where uα is from Gaussian-mixture confidence-sequence boundary, and set C0:=Θ. Then (Ct)t≥0 is a (1−α) confidence sequence for θ: Pθ(θ∈Ct for every t≥0)≥1−α(θ∈Θ). The claim is pointwise in θ and requires no measurable structure on Θ, independence, or identical distribution of the observations.

Facts & Assumptions

Given: Assume AC and all data, law, filtration, proxy, and tuning hypotheses in the Statement.

[F1]

Conditionally sub-Gaussian increments: for each fixed θ, time t≥1, and λ∈R, the conditional mgf of Xt−θ given Ft−1 is at most eλ2σ2/2 almost surely.

[F2]

The Gaussian mixture is a sub-Gaussian test supermartingale: under each Pθ, Mt(θ)=ρ/(tσ2+ρ)exp⁡(St(θ)2/[2(tσ2+ρ)]) is a nonnegative test supermartingale with M0(θ)=1.

[F3]

The Gaussian-mixture threshold is the stated square-root boundary: Mt(θ)≥1/α exactly when ∣St(θ)∣≥uα(tσ2).

[F4]

Discrete Ville inequality and anytime threshold validity: under AC, for every null law and each α∈(0,1), a nonnegative test supermartingale has P(sup⁡t≥0Mt≥1/α)≤α.

[F5]

Confidence sequences: a (1−α) confidence sequence has Ft-measurable membership events and covers each true parameter at all integer times with probability at least 1−α.

[A1]

The Axiom of Choice: AC supplies the conditional-expectation and test-supermartingale conventions used in [F2] and [F4].

Proof

1.1givenF1F5

Fix θ∈Θ. The process is adapted under Pθ, so each Xi for i≤t and hence Xˉt is Ft-measurable. Therefore {θ∈Ct} is Ft-measurable for every t≥1, and it is the whole space at t=0.

2.1givenF3step 1.1

For t≥1, if θ∉Ct, the interval in the Statement has closed endpoints, so ∣St(θ)∣>uα(tσ2). By [F3], this implies Mt(θ)≥1/α. Consequently the event that θ is ever excluded from Ct is contained in {sup⁡t≥0Mt(θ)≥1/α}.

3.1F2F4F5A1step 2.1∎

By [F2] and Ville's inequality [F4], the latter event has Pθ-probability at most α. Its complement therefore has probability at least 1−α and is contained in {θ∈Ct for all t≥0}. Since [F5] requires exactly these membership and coverage clauses, (Ct) is a confidence sequence.

Depends on

Used by

Dependency tree · two levels

24 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