Towards Formal Comparison of Ontology Linking, Mapping and Importing

Multiple distributed and modular ontology representation frameworks have recently appeared. They typically extend Description Logics (DL), with new constructs to represent relations between entities across several ontologies. Three kinds of constructs appear in the literature: link properties, found in E-connections, semantic mapping, found in Distributed Description Logics (DDL), and semantic imports, used in Package-based Description Logics (P-DL). In this work, we aim towards formal comparison of the expressive power of these frameworks, and thus also the ontology combination paradigms that they instantiate. Reduction from DDL to E-connections is already known. We present two new reductions, from P-DL to DDL and vice versa. These results show that there are similarities between these frameworks. However, due to the fact that none of the reductions is unconditional, it cannot be claimed that any of the three approaches is strictly more expressive than another.