Is a query rewriting/answering engine for Horn-SHIQ ontologies.

The core of the engine is a novel query rewriting technique which transforms an input conjunctive query q into a union Q of queries such that the answers of q over an ontology O = <T,A> coincide with the answers over A of a Datalog program comprising Q and some rules to complete A.

Architecture of Clipper

Our project is released under Apache 2 License and hosted on Github: https://github.com/ghxiao/clipper