{"type":"ScholarlyArticle","title":"Fact-Alternating Mutex Groups for Classical Planning (Extended Abstract)","authors":[{"name":"Daniel Fišer","slug":"daniel-fiser","given":"Daniel","family":"Fišer","affiliation":"Department of Computer Science , Faculty of Electrical Engineering , Czech Technical University in Prague , Czech Republic"},{"name":"Antonín Komenda","slug":"antonin-komenda","given":"Antonín","family":"Komenda","affiliation":"Department of Computer Science , Faculty of Electrical Engineering , Czech Technical University in Prague , Czech Republic"}],"abstract":"Mutex groups are defined in the context of STRIPS planning as sets of facts out of which, maximally, one can be true in any state reachable from the initial state. This  work provides a complexity analysis showing that inference of mutex groups is as hard as planning itself (PSPACE-Complete) and it also shows a tight relationship between mutex groups and graph cliques. Furthermore, we propose a new type of mutex group called a fact-alternating mutex group (fam-group) of which inference is NP-Complete. We introduce an algorithm for the inference of fam-groups based on integer linear programming that is complete with respect to the maximal fam-groups and we demonstrate that fam-groups can be beneficial in the translation of planning tasks into finite domain representation, for the detection of dead-end state and for the pruning of spurious operators. The experimental evaluation of the pruning algorithm shows a substantial increase in a number of solved tasks in domains from the optimal deterministic track of the last two planning competitions (IPC 2011 and 2014).","doi":"10.24963/ijcai.2018/793","url":"https://ijcai.org/proceedings/2018/793","pdf":"https://ijcai.org/proceedings/2018/0793.pdf","markdown":"https://ijcai.org/proceedings/2018/793.md","bibtex":"https://ijcai.org/proceedings/2018/bibtex/793","volume":{"slug":"2018","title":"Proceedings of the Twenty-Seventh International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2018","url":"https://ijcai.org/proceedings/2018/","year":2018,"location":"Stockholm","dates":"13-19 July 2018","editors":"Jérôme Lang","isbn":"978-0-9992411-2-7","publisher":"International Joint Conferences on Artificial Intelligence Organization","doi_prefix":"10.24963/ijcai.2018"},"section":"Journal track","track":"Journal track","number":793,"pages":{"first":5603,"last":5607},"keywords":["Planning and Scheduling: Theoretical Foundations of Planning","Planning and Scheduling: Planning Algorithms"],"videos":[],"references":[{"position":1,"raw":"[Alcázar and Torralba, 2015] Vidal Alcázar and Álvaro Tor- ralba. A reminder about the importance of computing and exploiting invariants in planning. In Proceedings of the Twenty-Fifth International Conference on Automated Planning and Scheduling (ICAPS), pages 2-6, 2015.","title":"Vidal Alcázar and Álvaro Torralba. A reminder about the importance of computing and exploiting invariants in planning","authors":"Torralba Alcázar","year":"2015","venue":"Proceedings of the Twenty-Fifth International Conference on Automated Planning and Scheduling (ICAPS)","doi":null,"url":null,"internal_url":null},{"position":2,"raw":"[Alcázar et al., 2013] Vidal Alcázar, Daniel Borrajo, Susana Fernández, and Raquel Fuentetaja. Revisiting regression in planning. In Proceedings of the Twenty-Third Interna- tional Joint Conference on Artificial Intelligence (IJCAI), pages 2254-2260, 2013.","title":"Revisiting regression in planning","authors":"Daniel Vidal Alcázar, Susana Borrajo, Raquel Fernández, Fuentetaja","year":"2013","venue":"Proceedings of the Twenty-Third International Joint Conference on Artificial Intelligence (IJCAI)","doi":null,"url":null,"internal_url":"/proceedings/2013/333"},{"position":3,"raw":"[Bäckström and Nebel, 1995] Christer Bäckström and Bern- hard Nebel. Complexity results for SAS+ planning. Com- putational Intelligence, 11:625-656, 1995.","title":"Christer Bäckström and Bernhard Nebel","authors":"Nebel Bäckström","year":"1995","venue":"Computational Intelligence","doi":null,"url":null,"internal_url":null},{"position":4,"raw":"[Bylander, 1994] Tom Bylander. The computational com- plexity of propositional STRIPS planning. Artif. Intell., 69(1-2):165-204, 1994.","title":"The computational complexity of propositional STRIPS planning","authors":"Tom Bylander","year":"1994","venue":"Artif. Intell","doi":null,"url":null,"internal_url":null},{"position":5,"raw":"[Edelkamp and Helmert, 1999] Stefan Edelkamp and Malte Helmert. Exhibiting knowledge in planning problems to minimize state encoding length. In Recent Advances in AI Planning, 5th European Conference on Planning (ECP), pages 135-147, 1999.","title":"Exhibiting knowledge in planning problems to minimize state encoding length","authors":"Helmert Edelkamp, Stefan Edelkamp, Malte Helmert","year":"1999","venue":"Recent Advances in AI Planning, 5th European Conference on Planning (ECP)","doi":null,"url":null,"internal_url":null},{"position":6,"raw":"[Fikes and Nilsson, 1971] Richard Fikes and Nils J. Nilsson. STRIPS: A new approach to the application of theorem proving to problem solving. Artif. Intell., 2(3/4):189-208, 1971.","title":"STRIPS: A new approach to the application of theorem proving to problem solving","authors":"Richard Fikes, Nils J Nilsson","year":"1971","venue":"Artif. Intell","doi":null,"url":null,"internal_url":"/proceedings/1971/63"},{"position":7,"raw":"[Fišer and Komenda, 2018] Daniel Fišer and Antonín Komenda. Fact-alternating mutex groups for classical planning. J. Artif. Intell. Res., 61:475-521, 2018.","title":"Fact-alternating mutex groups for classical planning","authors":"Komenda Fišer, Daniel Fišer, Antonín Komenda","year":"2018","venue":"J. Artif. Intell. Res","doi":null,"url":null,"internal_url":null},{"position":8,"raw":"[Gerevini and Schubert, 1998] Alfonso Gerevini and Lenhart K. Schubert. Inferring state constraints for domain-independent planning. In Proceedings of the Fif- teenth National Conference on Artificial Intelligence and Tenth Innovative Applications of Artificial Intelligence Conference (AAAI, IAAI), pages 905-912, 1998.","title":"Inferring state constraints for domain-independent planning","authors":"Alfonso Gerevini, Lenhart K Schubert","year":"1998","venue":"Proceedings of the Fifteenth National Conference on Artificial Intelligence and Tenth Innovative Applications of Artificial Intelligence Conference (AAAI, IAAI)","doi":null,"url":null,"internal_url":null},{"position":9,"raw":"[Gerevini and Schubert, 2000] Alfonso Gerevini and Lenhart K. Schubert. Discovering state constraints in DISCOPLAN: some new results. In Proceedings of the Seventeenth National Conference on Artificial Intelligence and Twelfth Conference on on Innovative Applications of Artificial Intelligence (AAAI, IAAI), pages 761-767, 2000.","title":"Discovering state constraints in DISCOPLAN: some new results","authors":"Alfonso Gerevini, Lenhart K Schubert","year":"2000","venue":"Proceedings of the Seventeenth National Conference on Artificial Intelligence and Twelfth Conference on on Innovative Applications of Artificial Intelligence (AAAI, IAAI)","doi":null,"url":null,"internal_url":null},{"position":10,"raw":"[Haslum and Geffner, 2000] Patrik Haslum and Hector Geffner. Admissible heuristics for optimal planning. In Proceedings of the Fifth International Conference on Artificial Intelligence Planning Systems (AIPS), pages 140-149, 2000.","title":"Admissible heuristics for optimal planning","authors":"Geffner Haslum, Patrik Haslum, Hector Geffner","year":"2000","venue":"Proceedings of the Fifth International Conference on Artificial Intelligence Planning Systems (AIPS)","doi":null,"url":null,"internal_url":null},{"position":11,"raw":"[Haslum, 2009] Patrik Haslum. h m (P ) = h 1 (P m ): Alter- native characterisations of the generalisation from h max to h m . In Proceedings of the 19th International Conference on Automated Planning and Scheduling (ICAPS), pages 354-357, 2009.","title":"Patrik Haslum. h m (P ) = h 1 (P m ): Alternative characterisations of the generalisation from h max to h m","authors":"Haslum","year":"2009","venue":"Proceedings of the 19th International Conference on Automated Planning and Scheduling (ICAPS)","doi":null,"url":null,"internal_url":null},{"position":12,"raw":"[Helmert, 2006] Malte Helmert. The Fast Downward plan- ning system. J. Artif. Intell. Res. (JAIR), 26:191-246, 2006.","title":"The Fast Downward planning system","authors":"Malte Helmert, Helmert","year":"2006","venue":"J. Artif. Intell. Res. (JAIR)","doi":null,"url":null,"internal_url":null},{"position":13,"raw":"[Helmert, 2009] Malte Helmert. Concise finite-domain rep- resentations for PDDL planning tasks. Artif. Intell., 173(5- 6):503-535, 2009.","title":"Concise finite-domain representations for PDDL planning tasks","authors":"Malte Helmert, Helmert","year":"2009","venue":"Artif. Intell","doi":null,"url":null,"internal_url":null},{"position":14,"raw":"[Karp, 1972] Richard M. Karp. Reducibility among com- binatorial problems. In Proceedings of a symposium on the Complexity of Computer Computations, pages 85-103, 1972.","title":"Reducibility among combinatorial problems","authors":"Richard M Karp","year":"1972","venue":"Proceedings of a symposium on the Complexity of Computer Computations","doi":null,"url":null,"internal_url":null},{"position":15,"raw":"[Kautz and Selman, 1992] Henry A. Kautz and Bart Selman. Planning as satisfiability. In Tenth European Conference on Artificial Intelligence (ECAI), pages 359-363, 1992.","title":"Planning as satisfiability","authors":"Henry A Kautz, Bart Selman","year":"1992","venue":"Tenth European Conference on Artificial Intelligence (ECAI)","doi":null,"url":null,"internal_url":null},{"position":16,"raw":"[Lipovetzky et al., 2016] Nir Lipovetzky, Christian J. Muise, and Hector Geffner. Traps, invariants, and dead-ends. In Proceedings of the Twenty-Sixth International Conference on Automated Planning and Scheduling (ICAPS), pages 211-215, 2016.","title":"Traps, invariants, and dead-ends","authors":"Nir Lipovetzky, Christian J Muise, Hector Geffner","year":"2016","venue":"Proceedings of the Twenty-Sixth International Conference on Automated Planning and Scheduling (ICAPS)","doi":null,"url":null,"internal_url":null},{"position":17,"raw":"[Mukherji and Schubert, 2005] Proshanto Mukherji and Lenhart K. Schubert. Discovering planning invariants as anomalies in state descriptions. In Proceedings of the Fifteenth International Conference on Automated Planning and Scheduling (ICAPS), pages 223-230, 2005.","title":"Discovering planning invariants as anomalies in state descriptions","authors":"Schubert Mukherji, Proshanto Mukherji, Lenhart K Schubert","year":"2005","venue":"Proceedings of the Fifteenth International Conference on Automated Planning and Scheduling (ICAPS)","doi":null,"url":null,"internal_url":null},{"position":18,"raw":"[Mukherji and Schubert, 2006] Proshanto Mukherji and Lenhart K. Schubert. State-based discovery and verifica- tion of propositional planning invariants. In Proceedings of the 2006 International Conference on Artificial Intelligence (ICAI), pages 465-471, 2006.","title":"State-based discovery and verification of propositional planning invariants","authors":"Schubert Mukherji, Proshanto Mukherji, Lenhart K Schubert","year":"2006","venue":"Proceedings of the 2006 International Conference on Artificial Intelligence (ICAI)","doi":null,"url":null,"internal_url":null},{"position":19,"raw":"[Rintanen, 2000] Jussi Rintanen. An iterative algorithm for synthesizing invariants. In Proceedings of the Seventeenth National Conference on Artificial Intelligence and Twelfth Conference on on Innovative Applications of Artificial In- telligence (AAAI, IAAI), pages 806-811, 2000.","title":"An iterative algorithm for synthesizing invariants","authors":"Jussi Rintanen","year":"2000","venue":"Proceedings of the Seventeenth National Conference on Artificial Intelligence and Twelfth Conference on on Innovative Applications of Artificial Intelligence (AAAI, IAAI)","doi":null,"url":null,"internal_url":null},{"position":20,"raw":"[Rintanen, 2008] Jussi Rintanen. Regression for classical and nondeterministic planning. In Proceedings of the 18th European Conference on Artificial Intelligence (ECAI), pages 568-572, 2008.","title":"Jussi Rintanen. Regression for classical and nondeterministic planning","authors":"Rintanen","year":"2008","venue":"Proceedings of the 18th European Conference on Artificial Intelligence (ECAI)","doi":null,"url":null,"internal_url":null},{"position":21,"raw":"[Sideris and Dimopoulos, 2010] Andreas Sideris and Yan- nis Dimopoulos. Constraint propagation in propositional planning. In Proceedings of the 20th International Con- ference on Automated Planning and Scheduling (ICAPS), pages 153-160, 2010.","title":"Constraint propagation in propositional planning","authors":"Dimopoulos Sideris, Andreas Sideris, Yannis Dimopoulos","year":"2010","venue":"Proceedings of the 20th International Conference on Automated Planning and Scheduling (ICAPS)","doi":null,"url":null,"internal_url":null},{"position":22,"raw":"[Torralba and Alcázar, 2013] Álvaro Torralba and Vidal Alcázar. Constrained symbolic search: On mutexes, BDD minimization and more. In Proceedings of the Sixth An- nual Symposium on Combinatorial Search (SOCS), pages 175-183, 2013.","title":"Constrained symbolic search: On mutexes, BDD minimization and more","authors":"Alcázar Torralba, Álvaro Torralba, Vidal Alcázar","year":"2013","venue":"Proceedings of the Sixth Annual Symposium on Combinatorial Search (SOCS)","doi":null,"url":null,"internal_url":null}],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}