Kowalski and Sergot's Event Calculus, abbreviated EC, is a simple temporal formalism designed to model situations characterized by a set of events, whose occurrences have the effect of starting or terminating the validity of determined properties. Given a possibly incomplete description of when these events take place and of the properties they affect, EC is able to determine the maximal validity intervals, or MVIs, over which a property holds uninterruptedly. The algorithm EC relies on for the verification or calculation of MVIs is polynomial and it can advantageously be implemented as a logic program.
Numerous extensions of EC have been proposed in order to increase its expressive power while maintaining tractability. Interesting results have been achieved with the introduction of preconditions and modal operators.
| Iliano Cervesato |