@inproceedings{wang-etal-2026-sppo,
    title = "{SPPO}: Sequence-Level {PPO} for Long-Horizon Reasoning Tasks",
    author = "Wang, Tianyi  and
      Li, Yixia  and
      Li, Long  and
      Chen, Yibiao  and
      Huang, Shaohan  and
      Chen, Yun  and
      Li, Peng  and
      Liu, Yang  and
      Chen, Guanhua",
    editor = "Liakata, Maria  and
      Moreira, Viviane P.  and
      Zhang, Jiajun  and
      Jurgens, David",
    booktitle = "Proceedings of the 64th Annual Meeting of the {A}ssociation for {C}omputational {L}inguistics (Volume 1: Long Papers)",
    month = jul,
    year = "2026",
    address = "San Diego, California, United States",
    publisher = "Association for Computational Linguistics",
    url = "https://preview.aclanthology.org/ingest-acl/2026.acl-long.356/",
    pages = "7831--7853",
    ISBN = "979-8-89176-390-6"
}