Problem detail · source-aware

Fulek's Question on the Extremal Function of $L_3$

resolvedconfidence 70%

VibeMathed reports this item as resolved. VibeMath preserves that report as a source assertion and has not independently authored a plain-language mathematical explanation.

Precise statement

Fulek defined a weight-five three-row $0$-$1$ matrix $L_3$ and asked whether $\mathrm{ex}(n, L_3) = O(n)$. It is: every $r \times s$ matrix avoiding $L_3$ has at most $27r + 2s$ ones, so $6n - 8 \le \mathrm{ex}(n,L_3) \le 29n$ for $n \ge 5$. The same argument covers an infinite family of light three-row patterns, verifying a conjecture of Pettie and Tardos on linear light patterns for that family.

The source statement is reproduced for indexing with attribution. Mathematical correctness requires domain-expert or mechanical review. VibeMath has not independently audited statement fidelity, correctness, priority, or novelty.

What AI did

Codex (GPT-5.6), Claude Code (Fable 5)

The acknowledgement says the two systems were used for proof exploration, proof criticism, exposition and revision, with no specific step attributed, so the lowest tier applies.

Provider: OpenAI / Anthropic · Prompt public: unknown · Independence: unknown

Verification boundary

unreviewed

Single-author arXiv preprint; not yet peer-reviewed.

Correctness: unknown · statement fidelity: unaudited · peer review: none

Timeline

  1. arXiv:2607.16463 - Linear extremal bounds for a family of forbidden 0-1 matrices

    the companion pattern Fulek proposed alongside L_3 is not covered by this method

Known method families

argument (source-reported)

Source-reported tools: argument.

Independent: unknown · difference confidence: 0

What remains uncertain

VibeMath has not independently audited the mathematical statement, proof, or novelty claim.

  • VibeMath has not independently verified the mathematical claim.
  • AI-attempt independence and training-data exposure are unknown unless explicitly documented.
  • VibeMath has not independently audited the mathematical statement, proof, or novelty claim.