# Foundations for a Probabilistic Event Calculus

## TL;DR

This paper introduces PEC, a probabilistic event calculus framework that models causal and narrative information using possible worlds semantics, with an ASP implementation demonstrating soundness and completeness.

## Contribution

It presents PEC, a novel probabilistic event calculus language with a formal semantics and an ASP-based implementation, advancing reasoning about uncertain events.

## Key findings

- PEC effectively models probabilistic causal relations.
- The ASP implementation is sound and complete.
- Demonstrates reasoning capabilities in probabilistic domains.

## Abstract

We present PEC, an Event Calculus (EC) style action language for reasoning about probabilistic causal and narrative information. It has an action language style syntax similar to that of the EC variant Modular-E. Its semantics is given in terms of possible worlds which constitute possible evolutions of the domain, and builds on that of EFEC, an epistemic extension of EC. We also describe an ASP implementation of PEC and show the sense in which this is sound and complete.