{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,3]],"date-time":"2026-10-03T02:43:04Z","timestamp":1790995384147,"version":"4.1.0"},"publisher-location":"California","reference-count":0,"publisher":"International Joint Conferences on Artificial Intelligence Organization","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2019,8]]},"abstract":"<jats:p>Explainable planning is widely accepted as a prerequisite for\u00a0autonomous agents to successfully work with humans. While there has\u00a0been a lot of research on generating explanations of solutions to\u00a0planning problems, explaining the absence of solutions remains an open\u00a0and under-studied problem, even though such situations can be the\u00a0hardest to understand or debug. In this paper, we show that\u00a0hierarchical abstractions can be used to efficiently generate reasons\u00a0for unsolvability of planning problems. In contrast to related work on\u00a0computing certificates of unsolvability, we show that these methods\u00a0can generate compact, human-understandable reasons for unsolvability.\u00a0Empirical analysis and user studies show the validity\u00a0of our methods \u00a0as well as their computational efficacy on a number of benchmark\u00a0planning domains.<\/jats:p>","DOI":"10.24963\/ijcai.2019\/197","type":"proceedings-article","created":{"date-parts":[[2019,7,28]],"date-time":"2019-07-28T03:46:05Z","timestamp":1564285565000},"page":"1422-1430","source":"Crossref","is-referenced-by-count":29,"title":["Why Can\u2019t You Do That HAL? Explaining Unsolvability of Planning Tasks"],"prefix":"10.24963","author":[{"given":"Sarath","family":"Sreedharan","sequence":"first","affiliation":[{"name":"CIDSE, Arizona State University, Tempe, AZ 85281 USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Siddharth","family":"Srivastava","sequence":"additional","affiliation":[{"name":"CIDSE, Arizona State University, Tempe, AZ 85281 USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David","family":"Smith","sequence":"additional","affiliation":[{"name":"PSresearch"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Subbarao","family":"Kambhampati","sequence":"additional","affiliation":[{"name":"CIDSE, Arizona State University, Tempe, AZ 85281 USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"10584","event":{"name":"Twenty-Eighth International Joint Conference on Artificial Intelligence {IJCAI-19}","theme":"Artificial Intelligence","location":"Macao, China","acronym":"IJCAI-2019","number":"28","sponsor":["International Joint Conferences on Artificial Intelligence Organization (IJCAI)"],"start":{"date-parts":[[2019,8,10]]},"end":{"date-parts":[[2019,8,16]]}},"container-title":["Proceedings of the Twenty-Eighth International Joint Conference on Artificial Intelligence"],"original-title":[],"deposited":{"date-parts":[[2019,7,28]],"date-time":"2019-07-28T03:47:31Z","timestamp":1564285651000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ijcai.org\/proceedings\/2019\/197"}},"subtitle":[],"proceedings-subject":"Artificial Intelligence Research Articles","short-title":[],"issued":{"date-parts":[[2019,8]]},"references-count":0,"URL":"https:\/\/doi.org\/10.24963\/ijcai.2019\/197","relation":{},"subject":[],"published":{"date-parts":[[2019,8]]}}}