Teaching LLMs to Ask: Self-Querying Category-Theoretic Planning for Under-Specified Reasoning
Shuhui Qu
TL;DR
SQ-BCP introduces a principled framework for LLM-based planning under partial observability by explicitly modeling preconditions with Sat/Viol/Unk labels, and resolving unknowns through targeted self-querying and bridging actions. It integrates a bidirectional search with a pullback-based categorical verifier, while using a distance-based score solely for ranking and pruning. The approach achieves substantially lower resource-violation rates on WikiHow and RecipeNLG compared with strong baselines, without sacrificing plan quality, and its theoretical analysis guarantees termination and correctness under bounded assumptions. This work advances executable planning for natural-language tasks in open-world contexts, where critical facts are latent or withheld in prompts, and demonstrates practical improvements in feasibility that are relevant for real-world instruction following and task execution.
Abstract
Inference-time planning with large language models frequently breaks under partial observability: when task-critical preconditions are not specified at query time, models tend to hallucinate missing facts or produce plans that violate hard constraints. We introduce \textbf{Self-Querying Bidirectional Categorical Planning (SQ-BCP)}, which explicitly represents precondition status (\texttt{Sat}/\texttt{Viol}/\texttt{Unk}) and resolves unknowns via (i) targeted self-queries to an oracle/user or (ii) \emph{bridging} hypotheses that establish the missing condition through an additional action. SQ-BCP performs bidirectional search and invokes a pullback-based verifier as a categorical certificate of goal compatibility, while using distance-based scores only for ranking and pruning. We prove that when the verifier succeeds and hard constraints pass deterministic checks, accepted plans are compatible with goal requirements; under bounded branching and finite resolution depth, SQ-BCP finds an accepting plan when one exists. Across WikiHow and RecipeNLG tasks with withheld preconditions, SQ-BCP reduces resource-violation rates to \textbf{14.9\%} and \textbf{5.8\%} (vs.\ \textbf{26.0\%} and \textbf{15.7\%} for the best baseline), while maintaining competitive reference quality.
