Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Model-theoretic Characterizations of Existential Rule Languages   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.

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The categories of this paper are: nucl-ex
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The categories of this paper are: q-alg
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The categories of this paper are: hep-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ex
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The categories of this paper are: eess
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The categories of this paper are: math
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The categories of this paper are: chem-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: mtrl-th
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The categories of this paper are: adap-org
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The categories of this paper are: quant-ph
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The categories of this paper are: solv-int
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The categories of this paper are: nlin
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The categories of this paper are: funct-an
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The categories of this paper are: math-ph