PACT: From Credit Assignment to Critic Alignment
By Jiayan Fu, Hang Xu, Yong Zhang, Zhaokai Luo, Yao Hu, Dongyan Zhao, Mu Chuan
PACT formalizes token-level credit assignment through three regularity conditions (Completeness, Prefix Consistency, Neutrality) and proves they uniquely determine the credit, providing a unified basis for analyzing and improving actor-critic training procedures for LLM post-training.