Bäckström, C, Jonsson, P and Ordyniak, S orcid.org/0000-0003-1935-651X (2019) A Refined Understanding of Cost-optimal Planning with Polytree Causal Graphs. In: Proceedings of the Twenty-Eighth International Joint Conference on Artificial Intelligence. Twenty-Eighth International Joint Conference on Artificial Intelligence {IJCAI-19}, 10-16 Aug 2019, Macao, P.R. China. International Joint Conferences on Artificial Intelligence Organization , pp. 6126-6130. ISBN 9780999241141
Abstract
Complexity analysis based on the causal graphs of planning instances is a highly important research area. In particular, tractability results have led to new methods for constructing domain-independent heuristics. Important early examples of such results were presented by, for instance, Brafman & Domshlak and Katz & Keyder. More general results based on polytrees and bounding certain parameters were subsequently derived by Aghighi et al. and Ståhlberg. We continue this line of research by analyzing cost-optimal planning for instances with a polytree causal graph, bounded domain size and bounded depth. We show that no further restrictions are necessary for tractability, thus generalizing the previous results. Our approach is based on a novel method of closely analysing optimal plans: we recursively decompose the causal graph in a way that allows for bounding the number of variable changes as a function of the depth, using a reording argument and a comparison with prefix trees of known size. We then transform the planning instances into tree-structured constraint satisfaction instances.
Metadata
Item Type: | Proceedings Paper |
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Authors/Creators: |
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Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Computing (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 17 Nov 2020 13:40 |
Last Modified: | 17 Nov 2020 13:40 |
Status: | Published |
Publisher: | International Joint Conferences on Artificial Intelligence Organization |
Identification Number: | 10.24963/ijcai.2019/848 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:168089 |