Modularizing OWL Ontologies Using $E^{DDL} _{HQ^+}$ $mathcal{SHIQ}$

Ontology modularization concerns about extracting ontology units from ontologies and partitioning large ontologies to possibly interdependent ontology units. Each unit specifies a specific context for performing ontology maintenance, evolution and reasoning tasks, which nevertheless has to be combined with chunks of tasks performed in other units. The modularization task is affected by assumptions concerning the mutual relations between the domains covered by distinct units, as well as by the expressiveness of the language used for specifying knowledge in units and for connecting distinct units. This paper presents a tool for partitioning SHIQ ontologies into units. These units can be combined using subjective class-to-class correspondences, as well as by inter-unit link properties that can be subjected to cardinality restrictions, existential and universal quantifiers, be hierarchically related and be transitive. While the modularization algorithm incorporated in this tool implements a specific partitioning method, the underlying representation framework provides a range of modularization possibilities, from units connected via class correspondences, to highly intertwined units, combined with class correspondences and inter-unit properties associated with restrictions.