Learn the Ropes, Then Trust the Wins: Self-imitation with Progressive Exploration for Agentic Reinforcement Learning - Qin, Yulei; Tan, Xiaoyu; He, Zhengbao; Li, Gang; Lin, Haojia; Li, Zongyi; Xu, Zihan; Shi, Yuchen; Cai, Siqi; Rui, Renting; Cai, Shaofei; Cai, Yuzheng; et al. (International Conference on Learning Representations, 2026)