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Research paper

Claude OpusMathematical ReasoningAI Evaluation1stProof Benchmark

Claude Opus 4.6 on 1stProof: Evaluating AI on Research-Level Mathematics

Claude Opus 4.6 generated candidate solutions to ten research-level mathematics problems. This report records prompting behavior and output completeness; mathematical correctness remains unverified in this publication.

Updated September 23, 2026 · Editorial correction dated 2026-09-23; the current repository link replaces an unavailable historical endpoint. No new experiment or independent reproduction is claimed.

Scope Claude Opus 4.6, ten First Proof problems, six prompting strategies and a reported 80+ API calls from February 2026. Limitations and artifacts

Abstract

We report a February 2026 evaluation of Claude Opus 4.6 on the ten First Proof mathematics problems, using six prompting strategies and more than 80 API calls. The original logs are described as containing candidate solutions for every problem, with extended-thinking calls sometimes exhausting their output budget before producing a final response. A continuation procedure produced final candidate answers. Output completeness and agreement do not establish proof validity. As of this editorial revision, this publication contains no completed problem-by-problem correctness verification; the original February 13 release deadline is historical.

On this page
  1. Verification update, September 22, 2026
  2. Introduction
  3. The ten questions
  4. Method
  5. Prompting strategies
  6. Results
  7. Prompting mode comparison
  8. Selected candidate arguments
  9. Q1: Mutual singularity of Φ⁴₃ measures
  10. Q2: Universal Whittaker functions
  11. Q6: ε-light vertex subsets
  12. Q7: Davis construction for lattices
  13. Reported token exhaustion
  14. Two-phase continuation
  15. Discussion
  16. Tools the responses cite
  17. Limitations
  18. Conclusion
  19. Data availability
  20. References
  21. Contributions and revision

Verification update, September 22, 2026

This publication does not contain a completed problem-by-problem correctness review of the candidate solutions. The original February 13 answer-release deadline has passed and is not a current reason to call verification pending. The benchmark paper was subsequently revised in March 2026; that update is not a verification of this experiment. A current public experiment repository is linked below, but repository availability does not establish a later verification outcome or mathematical correctness.

All answer summaries below are model-generated candidates, including claims that may be wrong. Counts of completed responses and agreement are not mathematical accuracy scores.

Introduction

The 1stProof Benchmark presented ten research-level mathematics problems whose answers were initially withheld. Created by mathematicians from Stanford, Harvard, Yale, EPFL, Columbia, and other leading institutions, these problems emerged from active mathematical research—not textbooks or competitions.

At the time of this experiment, the organizers had encrypted the answers for a limited period. This reduces direct access to those answers during that period; it does not exclude all related training material, contamination pathways or use of known mathematical results.

We evaluated Claude Opus 4.6 (claude-opus-4-6) in February 2026 using multiple prompting strategies to examine output behavior on these problems.

The ten questions

IDFieldProblem Summary
Q1Stochastic AnalysisMeasure equivalence under shifts on Φ⁴₃ measure space
Q2Representation TheoryExistence of universal Whittaker functions for Rankin-Selberg integrals
Q3Algebraic CombinatoricsMarkov chains on restricted partitions with ASEP polynomial stationary distribution
Q4Spectral Graph TheoryLogarithmic derivative inequality for real-rooted polynomial convolution
Q5Algebraic TopologySlice filtration characterization in G-equivariant stable categories
Q6Spectral Graph TheoryExistence of ε-light vertex subsets with linear size bounds
Q7Lattices in Lie GroupsUniform lattices with 2-torsion as fundamental groups of rationally acyclic manifolds
Q8Symplectic GeometryLagrangian smoothings of polyhedral surfaces with 4-valent vertices
Q9Tensor AnalysisPolynomial-time separability detection for tensor collections
Q10Numerical Linear AlgebraPreconditioned conjugate gradient for infinite-dimensional tensor problems

These span advanced topics rarely seen in AI benchmarks: stochastic PDEs, automorphic forms, symplectic topology, and algebraic K-theory.

Method

Prompting strategies

We test six distinct approaches:

Zero-Shot: Direct question presentation without scaffolding.

Chain-of-Thought: Explicit instruction to decompose reasoning step-by-step.

Multi-Attempt: Three independent attempts at temperatures 0.0, 0.5, and 1.0.

Self-Critique: Two-phase approach—initial solution followed by self-review and revision.

Extended Thinking: Anthropic’s adaptive thinking mode with effort: "max".

Extended Thinking + Continuation: Two-phase approach developed during this study.

All modes use a consistent system prompt emphasizing:

  • Publication-quality mathematical rigor
  • Peer-reviewed citations where applicable
  • Complete logical progression
  • Honest acknowledgment of uncertainty

The original report states that each response record includes:

  • SHA-256 hash of prompt and response
  • ISO 8601 timestamps
  • Token usage statistics
  • Model version and parameters

Hashes can detect changes to recorded content. They do not verify mathematical correctness or independently establish when an experiment occurred.

Results

Q#Candidate answerClaimed approachReported agreement
Q1Mutually SingularDichotomy theorem via Cameron-Martin7/7
Q2YesConstructive existence via Bernstein-Zelevinsky7/7
Q3YesMarkov chain construction with detailed balance7/7
Q4YesInequality via logarithmic convexity7/7
Q5NoCounterexample construction7/7
Q6YesRandom sampling with matrix concentration7/7
Q7YesDavis reflection group construction7/7
Q8YesLocal smoothing via symplectic surgery7/7
Q9YesPolynomial system via algebraic geometry7/7
Q10YesCondition number bounds with Kronecker structure7/7

The original table reports 7/7 agreement for each answer. Six strategies are listed, multi-attempt produces three outputs, and extended thinking alone produced no final answers. The aggregation behind 7/7 is not documented here and remains unreconciled. Agreement among related model outputs would not establish correctness even with a reconciled count.

Prompting mode comparison

ModeReported complete candidate responsesAvg Response Length
Zero-Shot10/10~2,500 tokens
Chain-of-Thought10/10~3,200 tokens
Multi-Attempt30/30~2,800 tokens
Self-Critique10/10~4,500 tokens
Extended Thinking0/100 tokens (exhausted)
Extended + Continuation10/10~4,200 tokens

Average length of the final response, by prompting mode

approximate tokens, as reported

Zero-shot10 of 10 complete
2,500
Chain-of-thought10 of 10 complete
3,200
Multi-attempt30 of 30 complete
2,800
Self-critique10 of 10 complete
4,500
Extended thinking0 of 10 complete
0
Extended + continuation10 of 10 complete
4,200
Figure 1. Extended thinking alone spent its whole 128,000-token budget on reasoning and returned no final answer. Response length and completion say nothing about whether an answer is correct.

Selected candidate arguments

These summaries preserve what the model reportedly argued; they are not endorsed proofs. In particular, a named theorem, plausible outline or citation is insufficient to establish that its hypotheses apply.

Q1: Mutual singularity of Φ⁴₃ measures

Problem: Are the Φ⁴₃ measure μ and its shift T_ψ*μ equivalent (same null sets)?

Candidate answer: No—they are mutually singular.

Candidate rationale (unverified): The response invokes the Cameron-Martin theorem. For Gaussian measures, equivalence requires the shift to lie in the Cameron-Martin space H. For the Φ⁴₃ measure (a non-Gaussian perturbation of the Gaussian free field), smooth shifts ψ have infinite Cameron-Martin norm, forcing mutual singularity.

The response claims to construct test functions distinguishing the measures. This argument, including its use of a Gaussian theorem for a non-Gaussian measure and its regularity assumptions, requires expert checking.

Q2: Universal Whittaker functions

Problem: Must there exist a Whittaker function W with a universal property for all generic representations π?

Candidate answer: Yes—such W exists.

Candidate strategy (unverified):

  1. Construct W using Bernstein-Zelevinsky theory of mirabolic restriction
  2. Show the modified Rankin-Selberg integral reduces to a constant independent of s
  3. Prove non-vanishing via Fourier analysis on compact groups

The response cites Jacquet-Piatetski-Shapiro-Shalika (1981) and Cogdell’s lectures. Those citations and their applicability have not been verified in this record.

Q6: ε-light vertex subsets

Problem: Does there exist c > 0 such that every graph has an ε-light subset of size ≥ cε|V|?

Candidate answer: Yes—with c ≈ 1/4.

Candidate strategy (unverified):

  1. Sample vertices with probability p = ε/2
  2. Expected size: εn/2 (linear in ε)
  3. Edges survive with probability p² = ε²/4 (quadratic in ε)
  4. Since ε² ≪ ε, the spectral condition εL - L_S ≽ 0 holds with high probability
  5. Matrix Chernoff bounds formalize the concentration

This outline invokes spectral graph and concentration techniques; the implication from expected edge counts to the claimed spectral inequality is not established by the outline.

Q7: Davis construction for lattices

Problem: Can a uniform lattice Γ with 2-torsion be the fundamental group of a compact manifold with rationally acyclic universal cover?

Candidate answer: Yes.

Candidate rationale (unverified): The response invokes the Davis reflection group trick. Given Γ < G semisimple with 2-torsion elements, construct a right-angled Coxeter group W acting on a CAT(0) cube complex. The Davis complex provides a contractible manifold on which Γ acts properly discontinuously with compact quotient.

The response claims that this construction gives the required manifold. The group action, torsion and quotient-manifold conditions require checking; a proper action alone does not establish the claimed manifold quotient.

Reported token exhaustion

For the reported extended-thinking configuration, the original experiment describes:

Extended Thinking (effort: "max")
Token Limit: 128,000
Thinking Tokens: 128,000
Response Tokens: 0
Stop Reason: max_tokens

The report records this output-budget exhaustion for all ten questions in that configuration. This is a historical observation about those calls, not a claim about every extended-thinking run or the current API.

Two-phase continuation

We developed a continuation approach:

  • Phase 1: Extended thinking with max effort (captures deep reasoning)
  • Phase 2: Feed thinking back, request final answer in standard mode

Results:

  • Phase 1: 128,000 tokens of mathematical reasoning
  • Phase 2: ~4,000 tokens of candidate solution text

The procedure reportedly yielded final candidate responses after the first phase. It does not establish their correctness.

Discussion

The original report describes theorem statements, lemmas, citations, varied approaches and acknowledgments of possible gaps. These are characteristics of the generated text. Rigor, citation accuracy and novelty require independent review and are not established by presentation alone.

Tools the responses cite

The candidate responses reportedly invoke the following mathematical tools:

Citation TypeExamples
Foundational theoryCameron-Martin theorem, Bernstein-Zelevinsky
Technical toolsMatrix Chernoff bounds, Tropp (2012)
Structural resultsDavis (1983), JPSS (1981)

The presence of these names does not establish valid reasoning, correct attribution, novelty or absence of training-data overlap.

Limitations

  • Correctness unresolved: No completed assessment is attached to this publication as of September 22, 2026
  • Unavailable original repository: The historical experiment URL returned HTTP 404 during the editorial revision
  • Accounting: The reported 7/7 agreement is not reconciled with the six strategies and repeated attempts
  • Single model: Only Claude Opus 4.6 evaluated
  • Notation loss: Some LaTeX formatting simplified in extraction

Conclusion

This experiment reports candidate answers to ten research-level problems and output-budget exhaustion in one historical prompting configuration. Its continuation procedure reportedly produced final responses. The record does not establish a mathematical success rate. A problem-by-problem review of complete arguments, assumptions and citations is needed before making a correctness claim.

Data availability

Current experiment artifact: Lumi-node/1stProof-Opus-Experiment. This repository is available for inspection; this publication still does not provide a completed correctness-verification record.

The original report described its contents as:

  • All 80+ responses (JSON and Markdown)
  • SHA-256 verification hashes
  • Thinking traces (where captured)
  • Experiment scripts

References

[1] 1stProof Team. “First Proof: A Benchmark for Research-Level Mathematical Reasoning.” arXiv:2602.05192, 2026.

[2] Anthropic. “Claude Opus 4.6 Technical Documentation.” 2026.

[3] Davis, M. “Groups Generated by Reflections and Aspherical Manifolds.” Annals of Mathematics, 1983.

[4] Jacquet, H., Piatetski-Shapiro, I., Shalika, J. “Conducteur des Représentations du Groupe Linéaire.” Math. Ann., 1981.

[5] Tropp, J. “User-Friendly Tail Bounds for Sums of Random Matrices.” Found. Comput. Math., 2012.


Contributions and revision

Andrew Young is the human author responsible for this publication. Claude Opus 4.6 generated the evaluated candidate solutions; the original report also described Claude as assisting with the research. Model-generated work and self-critique do not provide independent verification or author accountability.

This September 22, 2026 editorial revision corrects status, attribution and claim scope. It adds no new experiment or correctness assessment.

Paper record

Scope

Claude Opus 4.6, ten First Proof problems, six prompting strategies and a reported 80+ API calls from February 2026.

Verification pending

Limitation

Candidate answers have no completed correctness assessment in this record. Agreement counts and output completeness must not be read as an accuracy score.

Artifacts

A current public experiment repository is linked in the body. This record does not identify a completed correctness-verification artifact or a run-by-run mapping for every claim.

Citation

Use this record when citing the current public version.

Andrew Young (2026). Claude Opus 4.6 on 1stProof: Evaluating AI on Research-Level Mathematics. Automate Capture Research. https://research.automate-capture.co/journals/1stproof-opus-evaluation/