@article{zhang_jiang_2022, 
  title={Characterizing the Program Expressive Power of Existential Rule Languages}, 
  volume={36}, 
  DOI={10.1609/aaai.v36i5.20540}, 
  abstractNote={<jats:p>Existential rule languages are a family of ontology languages that have been widely used in ontology-mediated query answering (OMQA). However, for most of them, the expressive power of representing domain knowledge for OMQA, known as the program expressive power, is not well-understood yet. In this paper, we establish a number of novel characterizations for the program expressive power of several important existential rule languages, including tuple-generating dependencies (TGDs), linear TGDs, as well as disjunctive TGDs. The characterizations employ natural model-theoretic properties, and automata-theoretic properties sometimes, which thus provide powerful tools for identifying the definability of domain knowledge for OMQA in these languages.</jats:p>}, 
  publisher={Association for the Advancement of Artificial Intelligence (AAAI)}, 
  author={Zhang, Heng and Jiang, Guifei}, 
  year={2022}, 
  month={Jun}
  }