Transforming and Encoding FTS for SAT Solving: What Helps, What Hurts (Extended Version)
This work addresses the problem of efficiently solving factored tasks for AI planning by exploring SAT-based methods, which could offer an alternative to existing heuristic search approaches.
This paper explores encoding factored tasks (FTS) into SAT for planning, a departure from traditional heuristic search methods. It proposes various encoding strategies for the factored transition relation and analyzes the impact of parallelism and common task transformations on SAT-based planner performance.
Factored tasks are a classical planning representation that extends SAS+ with limited forms of disjunctive preconditions, conditional effects, and angelic nondeterminism. This allows for a more compact representation of tasks than traditional formalisms such as STRIPS or SAS+, and supports a wide range of task transformations. However, existing planning approaches for factored tasks have been limited to heuristic search methods. In this work, we investigate how to encode factored tasks in SAT. We propose several ways to encode the tasks, focusing on different strategies for translating the factored transition relation into propositional logic. We also analyze how to exploit parallelism at various levels in this setting and study the impact of common task transformations on the performance of SAT-based planners.