SPIRAL: Self-Play on Zero-Sum Games Incentivizes Reasoning via Multi-Agent Multi-Turn Reinforcement Learning - Liu, Bo; Yu, Simon; Liu, Zichen; Guertler, Leon; Qi, Penghui; Balcells, Daniel; Liu, Mickel; Tan, Cheston; Shi, Weiyan; Lin, Min; Lee, Wee Sun; Jaques, Natasha (International Conference on Learning Representations, 2026)