Epistemic Ensembles in Semantic and Symbolic Environments (Extended Version with Proofs)
Rolf Hennicker, Alexander Knapp, Martin Wirsing
TL;DR
This paper develops a formal framework for epistemic ensembles, i.e., families of knowledge-based agents that dynamically share and update beliefs about themselves and others. It introduces a unified syntactic operational semantics for ensembles and develops two complementary mathematical interpretations: semantic environments built from classes of pointed Kripke states and symbolic environments grounded in a finite symbolic knowledge base. A central construct, Φ-equivalence, relates semantic and symbolic states by ensuring that a selected focus of formulas holds exactly as specified in the symbolic state, enabling updates to preserve this equivalence. The main result proves that Φ-equivalent ensemble configurations simulate each other and satisfy the same dynamic ensemble formulæ, providing a robust bridge between semantic and symbolic reasoning for dynamic epistemic ensembles. The work lays groundwork for scalable behavioural ensembles, epistemic planning, and integration with distributed local-state models and LLM-assisted development.
Abstract
An epistemic ensemble is composed of knowledge-based agents capable of retrieving and sharing knowledge and beliefs about themselves and their peers. These agents access a global knowledge state and use actions to communicate and cooperate, altering the collective knowledge state. We study two types of mathematical semantics for epistemic ensembles based on a common syntactic operational ensemble semantics: a semantic environment defined by a class of global epistemic states, and a symbolic environment consisting of a set of epistemic formulæ. For relating these environments, we use the concept of Φ-equivalence, where a class of epistemic states and a knowledge base are Φ-equivalent, if any formula of Φ holds in the class of epistemic states if, and only if, it is an element of the knowledge base. Our main theorem shows that Φ-equivalent configurations simulate each other and satisfy the same dynamic epistemic ensemble formulae.
