PeRL: Permutation-Enhanced Reinforcement Learning for Interleaved Vision-Language Reasoning. - Yizhen Zhang; Yang Ding; Shuoshuo Zhang; Xinchen Zhang; Haoling Li; Zhong-zhi Li; Peijie Wang; Jie Wu; Lei Ji; Yelong Shen; Yujiu Yang; Yeyun Gong (CoRR, 2025)