Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: From Conjunctive Queries to Instance Queries in Ontology-Mediated
  Querying   We consider ontology-mediated queries (OMQs) based on expressive description
logics of the ALC family and (unions) of conjunctive queries, studying the
rewritability into OMQs based on instance queries (IQs). Our results include
exact characterizations of when such a rewriting is possible and tight
complexity bounds for deciding rewritability. We also give a tight complexity
bound for the related problem of deciding whether a given MMSNP sentence is
equivalent to a CSP.

2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
16
The categories of this paper are: stat
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph