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Quasipolynomial-time solution of simple stochastic and turn-based stochastic mean-payoff games

Claims a deterministic algorithm with 2O((log⁡(L+2))2)2^{O((\log(L+2))^2)} bit operations that outputs the set of vertices of nonnegative value in finite turn-based stochastic mean-payoff games with signed binary rewards and arbitrary rational chance probabilities, and hence decides the threshold-1/2 problem for Condon's simple stochastic games in deterministic quasipolynomial time. The proof chooses an explicit discount of polynomial bit length and finds the discounted fixed point by a recursive labeling procedure. It does NOT give a polynomial-time algorithm, and it decides the threshold set rather than outputting values or strategies in the stated theorem.

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Occurred: Oct 5, 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 simple stochastic and turn-based stochastic mean-payoff games · Stochastic games in quasipolynomial time

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Unreleased internal OpenAI model
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VibeMathed record: Quasipolynomial-time solution of simple stochastic and turn-based stochastic mean-payoff games evidence for this event

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

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

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

Claims a deterministic algorithm with 2O((log⁡(L+2))2)2^{O((\log(L+2))^2)} bit operations that outputs the set of vertices of nonnegative value in finite turn-based stochastic mean-payoff games with signed binary rewards and arbitrary rational chance probabilities, and hence decides the threshold-1/2 problem for Condon's simple stochastic games in deterministic quasipolynomial time. The proof chooses an explicit discount of polynomial bit length and finds the discounted fixed point by a recursive labeling procedure. It does NOT give a polynomial-time algorithm, and it decides the threshold set rather than outputting values or strategies in the stated theorem. parent of this event

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