TL;DR
This paper introduces a new semantics for answering negated queries over existential rules using universal core models, providing syntactic conditions for safe evaluation and new reasoning techniques.
Contribution
It proposes universal core models for negation in existential rules, and identifies syntactic query fragments suitable for current chase implementations.
Findings
Defined universal core models for negation semantics
Identified syntactic query fragments for safe evaluation
Developed new reasoning techniques for existential rules with negation
Abstract
Ontology-based query answering with existential rules is well understood and implemented for positive queries, in particular conjunctive queries. The situation changes drastically for queries with negation, where there is no agreed-upon semantics or standard implementation. Stratification, as used for Datalog, is not enough for existential rules, since the latter still admit multiple universal models that can differ on negative queries. We therefore propose universal core models as a basis for a meaningful (non-monotonic) semantics for queries with negation. Since cores are hard to compute, we identify syntactic descriptions of queries that can equivalently be answered over other types of models. This leads to fragments of queries with negation that can safely be evaluated by current chase implementations. We establish new techniques to estimate how the core model differs from other…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
