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Quasipolynomial-time solution of mean-payoff games with binary weights

Claims a deterministic algorithm computing the exact set of vertices from which Max can force nonnegative liminf mean payoff, for arbitrary signed binary weights, self-loops and parallel edges, in 2O((log⁡(L+2))2)2^{O((\log(L+2))^2)} bit operations; a reduction gives exact rational values and optimal positional strategies for both players, energy-game minimum credits, and tropical feasibility tests within the same bound. A randomized companion of the same date gives a Las Vegas algorithm with a polynomial-time certificate check. It does NOT give a polynomial-time algorithm, which the paper names as a further improvement. Conflicting claim: Truffet (arXiv:2603.26423, and a 2025 HAL note) claims a strongly polynomial algorithm via tropical optimization; the randomized companion gives a small example on which the printed rule of version 4 loses the optimum, and makes no claim about the 2025 note.

Exact FrontierDelta

Prior state unknown→proved

Scope and record

Occurred: Sep 25, 2026

Delta type: SOURCE CLAIM

Assumptions: VibeMathed verification: unreviewed. Publication: announcement. AI contribution: ai-discovered. VibeMathed editorial classifications, scores, notes, relations, and dataset structure are CC BY 4.0. Source statements and linked content retain their own rights.

Canonical aliases: Quasipolynomial-time solution of mean-payoff games with binary weights · Mean-payoff games in quasipolynomial time

Confidence: Not scored

Registry verification: unreviewed · announcement · partial

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Attribution

VibeMathed
registry · event recorded by

Unreleased internal OpenAI model
model · ai model contributor · OpenAI

Artifacts and verifiers

Lean: randomized quasipolynomial mean-payoff algorithm (companion result)

lean artifact · pending

Artifact ↗
Lean comparator statement: RandomizedMeanPayoff

lean artifact · pending

Artifact ↗

Compute record

No linked compute attempts recorded.

Lineage and corrections

Lean: randomized quasipolynomial mean-payoff algorithm (companion result) evidence for this event

Quasipolynomial-time solution of mean-payoff games with binary weights parent of this event

This event attributed to Unreleased internal OpenAI model

Quasipolynomial-time solution of simple stochastic and turn-based stochastic mean-payoff games evidence for this event

Claims a deterministic algorithm computing the exact set of vertices from which Max can force nonnegative liminf mean payoff, for arbitrary signed binary weights, self-loops and parallel edges, in 2O((log⁡(L+2))2)2^{O((\log(L+2))^2)} bit operations; a reduction gives exact rational values and optimal positional strategies for both players, energy-game minimum credits, and tropical feasibility tests within the same bound. A randomized companion of the same date gives a Las Vegas algorithm with a polynomial-time certificate check. It does NOT give a polynomial-time algorithm, which the paper names as a further improvement. Conflicting claim: Truffet (arXiv:2603.26423, and a 2025 HAL note) claims a strongly polynomial algorithm via tropical optimization; the randomized companion gives a small example on which the printed rule of version 4 loses the optimum, and makes no claim about the 2025 note. parent of this event

Lean comparator statement: RandomizedMeanPayoff evidence for this event

Truffet, Max-Atom problem in strongly polynomial time (HAL note, 2025; not addressed by the release) evidence for this event

Companion: Mean-payoff parity games in quasipolynomial time evidence for this event

Companion: Randomized quasipolynomial-time mean-payoff games evidence for this event

VibeMathed record: Quasipolynomial-time solution of mean-payoff games with binary weights evidence for this event

Companion: Deterministic quasipolynomial-time mean-payoff games evidence for this event

Truffet, claimed strongly polynomial tropical LP method (arXiv:2603.26423 v4), rebutted by the randomized companion evidence for this event

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Quasipolynomial-time solution of mean-payoff games with binary weights — Mathematical Frontier Network