Towards a complete characterization of epistemic reasoning: The notion of trust?

Designing autonomous agents, that interact with others to perform complex tasks, has always been one of the main objective of the Artificial Intelligence community. For such systems to be employed in complex scenarios, where the in- formation about others is key (e.g., self-driving cars), it is necessary to define robust formalisms that allow each agent to act considering her beliefs on both: I) the state of the world; and ii) the other agents' per- spective of it. The branch of AI that studies such formalisms is known in literature as Multi-Agent Epistemic Planning (MEP). The epistemic action-based language mAρ, to the best of our knowledge, is the most comprehensive tool to model MEP domains but still lacks concepts that are necessary to reason on real-world scenarios. In this paper we introduce the actions (un)trustworthy announcement and (mis)trustworthy announcement for mAρ. These actions increase the language's expressiveness introducing the notion of trust, therefore allowing for a more profound representation of real-world scenarios. In particular, we will provide the characterization, along with some desired properties, of the aforementioned actions' transition functions. Finally, we will discuss the importance of formalizing the concept of trust in the MEP problem.