A Guided Tour through Some Extensions of the Event Calculus

Kowalski and Sergot's Event Calculus (EC) is a simple temporal formalism that, given a set of event occurrences, derives the maximal validity intervals (MVIs) over which properties initiated or terminated by these events hold. In this paper, we conduct a systematic analysis of EC by which we gain a better understanding of this formalism and determine ways of augmenting its expressive power. The keystone of this endeavor is the definition of an extendible formal specification of its functionalities. This formalization has the effects of casting MVIs determination as a model checking problem, of setting the ground for studying and comparing the expressiveness and complexity of various extensions of EC, and of establishing a semantic reference against which to verify the soundness and completeness of implementations. We extend the range of queries accepted by EC, which is limited to boolean combinations of MVI verification or computation requests, to support arbitrary quantification...

• Type: Journal
• Year: 2000
• Where: CI
• Authors: Iliano Cervesato, Massimo Franceschet, Angelo Montanari
• Keywords: CI 2000, Expressive Power, Maximal Validity Intervals, Simple Temporal Formalism