Speeding up Temporal Reasoning by Exploiting the Notion of Kernel of an Ordering Relation

In this paper, we consider the problem of expediting temporal reasoning about partially ordered events in Kowalski and Sergot's Event Calculus (EC). We show how the introduction of partial ordering heavily increases the computational complexity of deriving Maximal Time Intervals (MVIs). Then, we provide a precise characterization of what EC actually does to compute MVIs, and propose a solution to do it efficiently when only incomplete information about event ordering is available.