Fuzzy Categorical Planning: Autonomous Goal Satisfaction with Graded Semantic Constraints
Shuhui Qu
TL;DR
The paper tackles planning in the presence of vagueness by extending category-theoretic planning with graded action applicability, while preserving crisp executability through pullback verification. It grounds vague predicates with an LLM using k-sample median, and composes plan quality via the Łukasiewicz t-norm, enabling explicit degradation tracking across multi-step plans. A bidirectional search with fuzzy propagation and residuation-based backward requirements enables meeting-in-the-middle planning under graded constraints, with plan acceptance controlled by explicit α-cuts. Empirically, FCP achieves competitive success on PDDL3 preferences/oversubscription and outperforms baselines on RecipeNLG-Subs in terms of feasibility and constraint satisfaction, while showing robustness to aggregation, chunking, and t-norm choices. The work demonstrates a practical pathway to integrate semantic vagueness into symbolic planning for real-world tasks, with implications for natural-language instruction following and mixed-initiative planning.
Abstract
Natural-language planning often involves vague predicates (e.g., suitable substitute, stable enough) whose satisfaction is inherently graded. Existing category-theoretic planners provide compositional structure and pullback-based hard-constraint verification, but treat applicability as crisp, forcing thresholding that collapses meaningful distinctions and cannot track quality degradation across multi-step plans. We propose Fuzzy Category-theoretic Planning (FCP), which annotates each action (morphism) with a degree in [0,1], composes plan quality via a t-norm Lukasiewicz, and retains crisp executability checks via pullback verification. FCP grounds graded applicability from language using an LLM with k-sample median aggregation and supports meeting-in-the-middle search using residuum-based backward requirements. We evaluate on (i) public PDDL3 preference/oversubscription benchmarks and (ii) RecipeNLG-Subs, a missing-substitute recipe-planning benchmark built from RecipeNLG with substitution candidates from Recipe1MSubs and FoodKG. FCP improves success and reduces hard-constraint violations on RecipeNLG-Subs compared to LLM-only and ReAct-style baselines, while remaining competitive with classical PDDL3 planners.
