What if no hybrid reasoner is available? Hybrid MKNF in multi-context systems

In open environments, agents need to reason with knowledge from varioussources, represented in different languages. Multi-Context Systems (MCSs) al-low for the integration of knowledge from different heterogeneous sources in aneffective and modular way. Whereas most knowledge bases (contexts) typicallyconsidered within an MCS are written in some description logic or some non-monotonic rule-based language, sometimes more expressive languages that com-bine the features of both these paradigms are necessary, such as Hybrid MKNF.However, since agents may not have access to specialised reasoners for contextsusing all these languages, it proves useful to have tools that equivalently simplifyor transform a given MCS into another MCS that only uses the reasoners that areavailable.In this paper, we thoroughly investigate the relation between MCSs and HybridMKNF. We provide a number of transformations that show that Hybrid MKNFknowledge bases can be embedded into MCSs without the need for specific MKNFreasoners. To complete the picture, we also show that when an MKNF reasoneris available, it can be used to handle several description logic and rule contextsjoined into a single MKNF context. Furthermore, we show that we can encapsulatethe non-monotonic transfer of information between different contexts in one rulelanguage context, allowing e.g. the use of external non-monotonic reasoners.