The Epistemic Planning Domain Definition Language: Official Guideline

TL;DR

The paper introduces EPDDL, a standardized language for epistemic planning based on Dynamic Epistemic Logic, enabling uniform task specification and facilitating benchmarking and interoperability.

Contribution

EPDDL provides a formal, PDDL-like language capturing DEL semantics, addressing fragmentation and enabling systematic evaluation in epistemic planning.

Findings

EPDDL captures the full DEL semantics for epistemic actions.

It enables uniform specification and benchmarking of epistemic planning tasks.

EPDDL facilitates interoperability and reproducibility in the field.

Abstract

Epistemic planning extends (multi-agent) automated planning by making agents' knowledge and beliefs first-class aspects of the planning formalism. One of the most well-known frameworks for epistemic planning is Dynamic Epistemic Logic (DEL), which offers an rich and natural semantics for modelling problems in this setting. The high expressive power provided by DEL make DEL-based epistemic planning a challenging problem to tackle both theoretically, and in practical implementations. As a result, existing epistemic planners often target different DEL fragments, and typically rely on ad hoc languages to represent benchmarks, and sometimes no language at all. This fragmentation hampers comparison, reuse, and systematic benchmark development. We address these issues by introducing the Epistemic Planning Domain Definition Language (EPDDL). EPDDL provides a unique PDDL-like representation that captures the entire DEL semantics, enabling uniform specification of epistemic planning tasks. Our main contributions are: 1. A formal development of abstract event models, a novel representation for epistemic actions used to define the semantics of our language; 2. A formal specification of EPDDL's syntax and semantics grounded in DEL with abstract event models. Through examples of representative benchmarks, we illustrate how EPDDL facilitates interoperability, reproducible evaluation, and future advances in epistemic planning.