We define a nonmonotonic formalism that shares some features with three other systems of nonmonotonic reasoning---default logic, logic programming with strong negation, and nonmonotonic causal logic---and study its possibilities as a language for describing actions.

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In Technical Communications of the International Conference on Logic Programming 2012.

@incollection{lif12, title={Two-valued logic programs}, author={Vladimir Lifschitz}, booktitle={Technical Communications of the International Conference on Logic Programming}, url="http://www.cs.utexas.edu/users/ai-lab?lif12", year={2012} }