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Existing methods for dealing with knowledge updates differ greatly depending on the underlying knowledge representation formalism. When Classical Logic is used, update operators are typically based on manipulating the knowledge base on the model-theoretic level. On the opposite side of the spectrum stand the semantics for updating Answer-Set Programs where(More)
We introduce an abstract update framework based on viewing a knowledge base as the set of sets of models of 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(More)
Normative systems have been advocated as an effective tool to regulate interaction in multi-agent systems. Logic programming rules intuitively correspond to conditional norms, and their semantics is based on the closed world assumption, which allows default negation, often used in norms. However, there are cases where the closed world assumption is clearly(More)
In open environments, agents need to reason with knowledge from various sources, represented in different languages. Multi-Context Systems (MCSs) allow for the integration of knowledge from different heterogeneous sources in an effective and modular way. Whereas most knowledge bases (contexts) typically considered within an MCS are written in some(More)
In this paper we investigate the relationship between Multi-Context Systems and Hybrid MKNF Knowledge Bases. Multi-Context Systems provide an effective and modular way to integrate knowledge from different heterogeneous sources (contexts) through so-called bridge rules. Hybrid MKNF Knowledge Bases, based on the logic of minimal knowledge and negation as(More)
In this extended abstract we borrow an example from the Portuguese Penal Code to advocate that norms used to regulate interaction in human societies, just as those used in multi-agent systems, require the joint use of the features based on the Closed World Assumption of rules in Logic Programming and those based on the Open World Assumption of ontologies in(More)