arXiv Computation and Language By Peien Ding, Hui Li, Yuhan Liu, Jinsong Su

LAMB: Latent Multi-Hypothesis Beliefs for Long-Horizon Large Language Agents

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The paper introduces LAMB, a recurrent framework that stores latent multi‑hypothesis beliefs for long‑horizon language agents. LAMB separates a shared Common state containing interaction evidence from weighted Delta components representing competing hypotheses, and updates these hypotheses using relative evidence from action‑outcome predictions without generating textual memory. Experiments on ALFWorld, BabyAI, ScienceWorld, and Crafter show that LAMB matches or surpasses prior methods, notably improving success rates and reducing redundant actions.

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