Finite Groundings for ASP with Functions: A Journey through Consistency

Finite Groundings for ASP with Functions: A Journey through Consistency

Lukas Gerlach, David Carral, Markus Hecher

Proceedings of the Thirty-Third International Joint Conference on Artificial Intelligence
Main Track. Pages 3386-3394. https://doi.org/10.24963/ijcai.2024/375

Answer set programming (ASP) is a logic programming formalism used in various areas of artificial intelligence like combinatorial problem solving and knowledge representation and reasoning. It is known that enhancing ASP with function symbols makes basic reasoning problems highly undecidable. However, even in simple cases, state of the art reasoners, specifically those relying on a ground-and-solve approach, fail to produce a result. Therefore, we reconsider consistency as a basic reasoning problem for ASP. We show reductions that give an intuition for the high level of undecidability. These insights allow for a more fine-grained analysis where we characterize ASP programs as "frugal" and "non-proliferous". For such programs, we are not only able to semi-decide consistency but we also propose a grounding procedure that yields finite groundings on more ASP programs with the concept of "forbidden" facts.
Keywords:
Knowledge Representation and Reasoning: KRR: Knowledge representation languages
Knowledge Representation and Reasoning: KRR: Computational complexity of reasoning
Knowledge Representation and Reasoning: KRR: Logic programming
Knowledge Representation and Reasoning: KRR: Non-monotonic reasoning