Exploiting Justifications for Lazy Grounding of Answer Set Programs

Tutkimustuotos: Artikkeli kirjassa/konferenssijulkaisussavertaisarvioitu

Tutkijat

Organisaatiot

  • KU Leuven

Kuvaus

Answer set programming (ASP) is an established knowledge representation formalism. Lazy grounding avoids the so-called grounding bottleneck of ASP by interleaving grounding and solving; this technique was recently extended to work with conflict-driven clause learning. Unfortunately, it often happens that such a lazy grounding ASP system, at the fixpoint of the evaluation, arrives at an assignment that contains literals that are true but unjustified. The system then is unable to determine the actual causes of the situation and falls back to chronological backtracking, potentially wasting an exponential amount of time. In this paper, we show how top-down query mechanisms can be used to analyze the situation, learn a new clause or nogood, and backjump further in the search tree. Contributions include a rephrasing of lazy grounding in terms of justifications and algorithms to construct relevant justifications without grounding. Initial experiments indicate that the newly developed techniques indeed allow for an exponential speed-up.

Yksityiskohdat

AlkuperäiskieliEnglanti
OtsikkoProceedings of the 27th International Joint Conference on Artificial Intelligence, IJCAI 2018
ToimittajatJérôme Lang
TilaJulkaistu - 2018
OKM-julkaisutyyppiA4 Artikkeli konferenssijulkaisuussa
TapahtumaInternational Joint Conference on Artificial Intelligence - Stockholm, Ruotsi
Kesto: 13 heinäkuuta 201819 heinäkuuta 2018
Konferenssinumero: 27
http://www.ijcai-18.org

Conference

ConferenceInternational Joint Conference on Artificial Intelligence
LyhennettäIJCAI
MaaRuotsi
KaupunkiStockholm
Ajanjakso13/07/201819/07/2018
www-osoite

ID: 21593804