It plays a central role in intelligent agent systems to model agents' epistemic states and their changes. Asynchrony plays a key role in distributed systems, in which the messages transmitted may not be received instantly by the agents. Epistemic interaction behaviours can change agents' epistemic states, while the latter will affect the former. So far, the literature mainly focuses on formalizing the change of epistemic state after receiving information. 

To model epistemic interactions between agents with epistemic states, a research team led by Huili Xing published their new research on 11 Mar 2024 in Frontiers of Computer Science co-published by Higher Education Press and Springer Nature.

The team proposed a process calculus called the e-calculus for modelling epistemic interactions between agents with epistemic states in the concurrency situations by enriching the classical π-calculus with the operators for passing basic facts and applying the well-known action model logic to describe agents' epistemic states. 

Figure 1: The language of the e-calculus

The e-calculus can be adopted to characterize synchronous and asynchronous communications between agents. To capture the asynchrony, a shared buffer pool is constructed to store the basic facts announced and each agent reads these facts from this buffer pool in different orders. Compared with the typical methods capturing the asynchrony (Asynchronous Announcement Logic and Epistemic Concurrent Constraint Programming (ECCP)) in the literature in detail, the e-calculus has its own characteristics and advantages in capturing asynchrony. In particular, the e-calculus can realize ECCP.

The different e-calculus can be presented by adopting the available formal methods to model agents' epistemic states and epistemic interactions, and it is left to further work to construct the e-calculus oriented to different epistemic scenarios. The behaviour theory is one of the core theoretical topics of a process calculus, and the behavior theory of the e-calculus is left to the future work. 

DOI: 10.1007/s11704-023-3208-4