Classical logic event calculus as answer set programming
Joohyung Lee, Ravi Palla · 2008
Abstract. Recently, Ferraris, Lee and Lifschitz presented a generalized definition of a stable model that applies to the syntax of arbitrary firstorder sentences, under which a logic program is viewed as a special class of first-order sentences. The new definition of a stable model is similar to the definition of circumscription, and can even be characterized in terms of circumscription. In this paper, we show the opposite direction, that is, how to embed circumscription into the new stable model semantics, and based on this, how to turn some versions of the classical logic event calculus into the general language of stable models. By turning the latter to answer set programs under certain conditions, we show that answer set solvers can be used for classical logic event calculus reasoning, allowing more expressive query answering than what can be handled by the current SAT-based implementations of the event calculus. We prove the correctness of our translation method and compare our work with the related work by Mueller. 1