Model-theoretic Characterizations of Existential Rule Languages
Abstract
Existential rules, a.k.a. dependencies in databases, and Datalog+/- in knowledge representation and reasoning recently, are a family of important logical languages widely used in computer science and artificial intelligence. Towards a deep understanding of these languages in model theory, we establish model-theoretic characterizations for a number of existential rule languages such as (disjunctive) embedded dependencies, tuple-generating dependencies (TGDs), (frontier-)guarded TGDs and linear TGDs. All these characterizations hold for arbitrary structures, and most of them also work on the class of finite structures. As a natural application of these characterizations, complexity bounds for the rewritability of above languages are also identified.
Cite
@article{arxiv.2001.08688,
title = {Model-theoretic Characterizations of Existential Rule Languages},
author = {Heng Zhang and Yan Zhang and Guifei Jiang},
journal= {arXiv preprint arXiv:2001.08688},
year = {2020}
}
Comments
17 pages, 2 figures, the full version of a paper submitted to IJCAI 2020