Iterating revision

Abstract

In the previous chapter we presented some operators that could be used to perform revision in the AGM sense and action updates complying with Katsuno and Mendelzon's semantical characterisation of these operations. It is well known that even though the postulates capture the intuitions behind rational changes of belief and the expected properties of the execution of actions, they are severely limited by the lack of extra information supporting the representation of the current state of affairs or beliefs. Some of these limitations were discussed in Chapter 2 in the sections related to the iteration of the revision process. In particular, the realisation of the initial corpus of beliefs (or the description of the world in the case of action updates) into a unit with little structure (a formula in the finite case or a theory, otherwise) brings several difficulties to reasoning about more sophisticated scenarios. © 2010 Springer-Verlag Berlin Heidelberg.