Belief base change as priority change: A study based on dynamic epistemic logic

Abstract

AGM's belief revision is one of the main paradigms in the study of belief change operations. In this context, belief bases (prioritised bases) have been primarily used to specify the agent's belief state. While the connection of iterated AGM-like operations and their encoding in dynamic epistemic logics have been studied before, few works considered how well-known postulates from iterated belief revision theory can be characterised by means of belief bases. Particularly, it has been shown that some postulates can be characterised through transformations in priority graphs, while others may not be represented that way. This work investigates the expressive power of prioritized bases, employing priority graphs as a representation for an agent's belief state and of transformations on such bases as representations for iterated relational belief change operators. As such, we propose a new representation for an agent's belief state, which we show can be used to characterize different iterated belief change postulates not previously representable using transformations on priority graphs.