Forgetting and Unfolding for Existential Rules

Authors

  • Zhe Wang Griffith University
  • Kewen Wang Griffith University
  • Xiaowang Zhang Tianjin University

Keywords:

Ontology, Rules, Forgetting

Abstract

Existential rules, a family of expressive ontology languages, inherit desired expressive and reasoning properties from both description logics and logic programming. On the other hand, forgetting is a well studied operation for ontology reuse, obfuscation and analysis. Yet it is challenging to establish a theory of forgetting for existential rules. In this paper, we lay the foundation for a theory of forgetting for existential rules by developing a novel notion of unfolding. In particular, we introduce a definition of forgetting for existential rules in terms of query answering and provide a characterisation of forgetting by the unfolding. A result of forgetting may not be expressible in existential rules, and we then capture the expressibility of forgetting by a variant of boundedness. While the expressibility is undecidable in general, we identify a decidable fragment. Finally, we provide an algorithm for forgetting in this fragment.

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Published

2018-04-25

How to Cite

Wang, Z., Wang, K., & Zhang, X. (2018). Forgetting and Unfolding for Existential Rules. Proceedings of the AAAI Conference on Artificial Intelligence, 32(1). Retrieved from https://ojs.aaai.org/index.php/AAAI/article/view/11552

Issue

Section

AAAI Technical Track: Knowledge Representation and Reasoning