Disjunctive logic programming with types and objects: The DLV+ system

The paper presents DLV+, a Disjunctive Logic Programming (DLP) system with object-oriented constructs, including classes, objects, (multiple) inheritance, and types. DLV+ is built on top of DLV (a state-of-the art DLP system), and provides a graphical user interface that allows one to specify, update, browse, query, and reason on knowledge bases. Two strong points of the system are the powerful type-checking mechanism and the advanced interface for visual querying.DLV+ is already used for the development of knowledge based applications for information extraction and text classification.