Heterogeneous nonmonotonic multi-context systems (MCS) permit different
logics to be used in different contexts, and link them via bridge rules. We
investigate the role of symmetry detection and symmetry breaking in such
systems to eliminate symmetric parts of the search space and, thereby, simplify
the evaluation process. We propose a distributed algorithm that takes a local
stance, i.e., computes independently the partial symmetries of a context and,
in order to construct potential symmetries of the whole, combines them with
those partial symmetries returned by neighbouring contexts.
In the context of the Semantic Web, several approaches to the combination of
ontologies, given in terms of theories of classical first-order logic and rule
bases, have been proposed. They either cast rules into classical logic or limit
the interaction between rules and ontologies. Autoepistemic logic (AEL) is an
attractive formalism which allows to overcome these limitations, by serving as
a uniform host language to embed ontologies and nonmonotonic logic programs
into it. For the latter, so far only the propositional setting has been
considered.