We extend Clark's definition of a completed program and the definition of a loop formula due to Lin and Zhao to disjunctive logic programs. Our main result, generalizing the Lin/Zhao theorem, shows that answer sets for a disjunctive program can be characterized as the models of its completion that satisfy the loop formulas. The concept of a tight program and Fages' theorem are extended to disjunctive programs as well.

PS

In Proceedings of International Conference on Logic Programming (ICLP), 451-465, 2003.

@Inproceedings{lee03a, title={Loop Formulas for Disjunctive Logic Programs}, author={Joohyung Lee and Vladimir Lifschitz}, booktitle={Proceedings of International Conference on Logic Programming (ICLP)}, pages={451-465}, url="http://www.cs.utexas.edu/users/ai-lab/pub-view.php?PubID=929", year={2003} }