DuPO: Enabling Reliable Self-Verification via Dual Preference Optimization - She, Shuaijie; Bao, Yu; Lu, Yu; Xu, Lu; Li, Tao; Zhu, Wenhao; Zhang, Jianbing; Huang, Shujian; Cheng, Shanbo; Lu, Lu; Wang, Yuxuan (International Conference on Learning Representations, 2026)