{"type":"ScholarlyArticle","title":"Unchaining the Power of Partial Delete Relaxation, Part II: Finding Plans with Red-Black State Space Search","authors":[{"name":"Maximilian Fickert","slug":"maximilian-fickert","given":"Maximilian","family":"Fickert","affiliation":"Saarland University , Saarland Informatics Campus , Saarbrücken , Germany"},{"name":"Daniel Gnad","slug":"daniel-gnad","given":"Daniel","family":"Gnad","affiliation":"Saarland University , Saarland Informatics Campus , Saarbrücken , Germany"},{"name":"Joerg Hoffmann","slug":"joerg-hoffmann","given":"Joerg","family":"Hoffmann","affiliation":"Saarland University , Saarland Informatics Campus , Saarbrücken , Germany"}],"abstract":"Red-black relaxation in classical planning allows to interpolate between delete-relaxed and real planning. Yet the traditional use of relaxations to generate heuristics restricts relaxation usage to tractable fragments. How to actually tap into the red-black relaxation's interpolation power? Prior work has devised red-black state space search (RBS) for intractable red-black planning, and has explored two uses: proving unsolvability, generating seed plans for plan repair. Here, we explore the generation of plans directly through RBS. We design two enhancements to this end: (A) use a known tractable fragment where possible, use RBS for the intractable parts; (B) check RBS state transitions for realizability, spawn relaxation refinements where the check fails. We show the potential merits of both techniques on IPC benchmarks.","doi":"10.24963/ijcai.2018/660","url":"https://ijcai.org/proceedings/2018/660","pdf":"https://ijcai.org/proceedings/2018/0660.pdf","markdown":"https://ijcai.org/proceedings/2018/660.md","bibtex":"https://ijcai.org/proceedings/2018/bibtex/660","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":"Planning and Scheduling","track":"Main track","number":660,"pages":{"first":4750,"last":4756},"keywords":["Heuristic Search and Game Playing: Heuristic Search","Planning and Scheduling: Search in Planning and Scheduling","Planning and Scheduling: Planning Algorithms"],"videos":[],"references":[{"position":1,"raw":"[Bäckström and Nebel, 1995] Christer Bäckström and Bernhard Nebel. 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