@article{250511225,
  title = {HAPO: Training Language Models to Reason Concisely via History-Aware Policy Optimization},
  author = {Chengyu Huang and Zhengxin Zhang and Claire Cardie},
  year = {2025},
  eprint = {2505.11225},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2505.11225v1},
}