“Gracefully Rewriting Into Non-recursive Datalog.”
Grind is a software tool to check for FO-rewritability of concept and conjunctive queries in EL ontologies, and to produce non-recursive datalog rewritings, if possible.
Peter Hansen, and Carsten Lutz. Computing FO-Rewritings in EL in Practice: from Atomic to Conjunctive Queries. In Proceedings of the 16th International Semantic Web Conference (ISWC 2017), 2017.
Paper (PDF) – BibTex entry
Peter Hansen, Carsten Lutz, İnanç Seylan, and Frank Wolter. Efficient Query Rewriting in the Description Logic EL and Beyond. In Proceedings of the 24th International Joint Conference on Artificial Intelligence (IJCAI 2015), 2015.
Paper (PDF) – BibTex entry
The picture on top is a derivative of "A skateboarder performing a nosegrind" by MattLaws, used under CC BY 2.0.