@article{implicithierarchicalgrpodecouplingtoolin,
  title = {Implicit Hierarchical GRPO: Decoupling Tool Invocation from Execution for Tool-Integrated Mathematical Reasoning},
  author = {Li Wang and Xiaohan Wang and Xiaodong Lu and Zipeng Zhang and Jinyang Wu and Jiajun Chai and Wei Lin and Guojun Yin},
  year = {2026},
  eprint = {2605.18500},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2605.18500},
}