Ontologies for Knowledge Graphs: Breaking the Rules

  title={Ontologies for Knowledge Graphs: Breaking the Rules},
  author={Markus Kr{\"o}tzsch and Veronika Thost},
Large-scale knowledge graphs (KGs) are widely used in industry and academia, and provide excellent use-cases for ontologies. We find, however, that popular ontology languages, such as OWL and Datalog, cannot express even the most basic relationships on the normalised data format of KGs. Existential rules are more powerful, but may make reasoning undecidable. Normalising them to suit KGs often also destroys syntactic restrictions that ensure decidability and low complexity. We study this issue… 

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