Generalized 3-Valued Belief States in Conformant Planning

Saurabh Fadnis, Jussi Rintanen

Abstract: The high complexity of planning with partial observability has motivated to find compact representations of belief state (sets of states) that reduce their size exponentially, including the 3-valued literal-based approximations by Baral et al. and tag-based approximations by Palacios and Geffner. We present a generalization of 3-valued literal-based approximations, and an algorithm that analyzes a succinctly represented planning problem to derive a set of formulas the truth of which accurately represents any reachable belief state. This set is not limited to literals and can contain arbitrary formulas. We demonstrate that a factored representation of belief states based on this analysis enables fully automated reduction of conformant planning problems to classical planning, bypassing some of the limitations of earlier approaches.