{"type":"ScholarlyArticle","title":"Eliminating Disjunctions in Answer Set Programming by Restricted Unfolding","authors":[{"name":"Jian-Min Ji","slug":"jian-min-ji","given":"Jian-Min","family":"Ji","affiliation":""},{"name":"Hai Wan","slug":"hai-wan","given":"Hai","family":"Wan","affiliation":""},{"name":"Kewen Wang","slug":"kewen-wang","given":"Kewen","family":"Wang","affiliation":""},{"name":"Zhe Wang","slug":"zhe-wang-2","given":"Zhe","family":"Wang","affiliation":""},{"name":"Chuhan Zhang","slug":"chuhan-zhang","given":"Chuhan","family":"Zhang","affiliation":""},{"name":"Jiangtao Xu","slug":"jiangtao-xu","given":"Jiangtao","family":"Xu","affiliation":""}],"abstract":"A disjunctive logic program under the answer set semantics can be equivalently translated to a normal logic program by the shifting transformation, if the program is head-cycle-free. In this paper, we provide an answer-set-preserving rewriting of a general disjunctive program to a normal program by first applying the unfolding transformation on atoms that prevent the program from being head-cycle-free, then shifting the resulting program. Different from other transformations that eliminate disjunctions in answer set programming, the new rewriting is efficient for almost head-cycle-free programs, i.e., programs that have only a few atoms that prevent them to be head-cycle-free. Based on the new rewriting, we provide an anytime algorithm to compute answer sets of a disjunctive program by calling solvers for normal logic programs. The experiment shows that the algorithm is efficient for some disjunctive programs. We also extend the rewriting to non-ground answer set programs on finite structures.","doi":null,"url":"https://ijcai.org/proceedings/2016/164","pdf":"https://ijcai.org/proceedings/2016/0164.pdf","markdown":"https://ijcai.org/proceedings/2016/164.md","bibtex":"https://ijcai.org/proceedings/2016/bibtex/164","volume":{"slug":"2016","title":"Proceedings of the Twenty-Fifth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2016","url":"https://ijcai.org/proceedings/2016/","year":2016,"location":"New York, NY, USA","dates":"9–15 July 2016","editors":"Subbarao Kambhampati","isbn":"978-1-57735-770-4; 978-1-57735-771-1","publisher":"AAAI Press / International Joint Conferences on Artificial Intelligence","doi_prefix":""},"section":null,"track":"","number":164,"pages":{"first":1130,"last":1136},"keywords":[],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}