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A Practical Acyclicity Notion for Query Answering Over Horn- $$\mathcal {SRIQ}$$ Ontologies [chapter]

David Carral, Cristina Feier, Pascal Hitzler
2016 Lecture Notes in Computer Science  
In this paper, we define a novel acyclicity notion which provides a sufficient condition for termination of the restricted chase over Horn-SRIQ TBoxes.  ...  Conjunctive query answering over expressive Horn Description Logic ontologies is a relevant and challenging problem which, in some cases, can be addressed by application of the chase algorithm.  ...  Introduction Conjunctive query (CQ) answering over expressive Description Logic (DL) ontologies is a key reasoning task which remains unsolved for many practical purposes.  ... 
doi:10.1007/978-3-319-46523-4_5 fatcat:kgxxkq4wffai7g5kdo755bakty

Reasoning and Query Answering in Description Logics [chapter]

Magdalena Ortiz, Mantas Šimkus
2012 Lecture Notes in Computer Science  
Query Answer A tuple of individuals a 1 , . . . , a n is called an (certain) answer for q(t 1 , . . . , t n ) over K if in every model I of K there is a match π for q such that π(t i ) = a i I for every  ...  horn , DL-Lite krom ) Queries in DLs The user can pose queries over the vocabulary of the ontology, the system performs reasoning to return all answers • Retrieve antibiotics that can be used to treat  ...  . 09) Idea: Given a KB T , A and a CQ q, obtain a FOL query q and an ABox A such that for every tuple a of constants, a is an answer for q over T , A iff a is an answer for q over A (using the usual DB  ... 
doi:10.1007/978-3-642-33158-9_1 fatcat:fzifcfpzwndgrng6jfjeldipxe

Detecting Chase (Non)Termination for Existential Rules with Disjunctions

David Carral, Irina Dragoste, Markus Krötzsch
2017 Proceedings of the Twenty-Sixth International Joint Conference on Artificial Intelligence  
The restricted chase is a sound and complete algorithm for conjunctive query answering over ontologies of disjunctive existential rules. We develop acyclicity conditions to ensure its termination.  ...  Experiments on real-world ontologies show that our acyclicity notions improve significantly over known criteria.  ...  By combining this with our previous acyclicity notions, we hope to decide the question of chase termination for most practical ontologies.  ... 
doi:10.24963/ijcai.2017/128 dblp:conf/ijcai/CarralDK17 fatcat:42ngbxpmdrfoli4on7m3g4cyjy

Real Time Reasoning in OWL2 for GDPR Compliance [article]

P.A. Bonatti, L. Ioffredo, I. Petrova, L. Sauro, I. R. Siahaan
2020 arXiv   pre-print
Moreover, we show how PL and PLR can be extended to support richer ontologies, by means of import-by-query techniques.  ...  We prove also some negative results, concerning the intractability of unrestricted reasoning in PL, and the limitations posed on ontology import.  ...  in Horn-SRIQ, too).  ... 
arXiv:2001.05390v1 fatcat:igusnjpdcbgglgqkne3mm6r5zu

On the Complexity of Semantic Integration of OWL Ontologies [article]

Yevgeny Kazakov, Denis Ponomaryov
2017 arXiv   pre-print
We propose a new mechanism for integration of OWL ontologies using semantic import relations.  ...  In this paper, we study the complexity of reasoning over ontologies with semantic import relations and establish a range of tight complexity bounds for various fragments of OWL.  ...  The importing mechanism is simple in that it does not require any significant modification of the underlying reasoning algorithms: in order to answer a query over an ontology with an import declaration  ... 
arXiv:1705.04719v1 fatcat:2zq5vd7yinba3o7somsmoqoot4

HermiT: An OWL 2 Reasoner

Birte Glimm, Ian Horrocks, Boris Motik, Giorgos Stoilos, Zhe Wang
2014 Journal of automated reasoning  
HermiT is based on the hypertableau calculus, and it supports a wide range of standard and novel optimisations that improve the performance of reasoning on real-world ontologies.  ...  the OWL 2 standard such as DL-safe rules, SPARQL queries, and description graphs.  ...  This is important since ontologies considered in practice often consist of mostly Horn axioms.  ... 
doi:10.1007/s10817-014-9305-1 fatcat:64hxriwsyndetfktyrqu7diwuq