A Unifying Perspective on Knowledge Updates

We introduce an abstract update framework based on viewing a knowledge base as theset of sets of modelsof its elements and performing updates by introducing additional interpretations –exceptions– to the sets of models of elements of the original knowledge base. In [36], an instantiation of this framework for performing rule updates has been shown to semantically characterise one of the syntax-basedrule update semantics. In this paper we show that the framework can also capture a wide range of both model- and formula-based belief update operators which constitute the formal underpinning of existing approaches toontology updates. Exception-driven operators thus form a unifying perspective on both ontology and rule updates, opening new possibilities for addressingupdates of hybrid knowledge basesconsisting of both an ontology and a rule component.