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This system description paper introduces the OWL 2 reasoner HermiT. The reasoner is fully compliant with the OWL 2 Direct Semantics as standardised by the World Wide Web Consortium (W3C). 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(More)
This paper introduces Konclude, a high-performance reasoner for the Description Logic SROIQV. The supported ontology language is a superset of the logic underlying OWL 2 extended by nominal schemas, which allows for expressing arbitrary DL-safe rules. Konclude’s reasoning core is primarily based on the well-known tableau calculus for expressive Description(More)
Ontology classification—the computation of the subsumption hierarchies for classes and properties—is a core reasoning service provided by all OWL reasoners known to us. A popular algorithm for computing the class hierarchy is the so-called Enhanced Traversal (ET) algorithm. In this paper we present a new classification algorithm that attempts to address(More)
The OWL reasoner evaluation (ORE) workshop brings together reasoner developers and ontology engineers in order to discuss and evaluate the performance and robustness of modern reasoners on OWL ontologies. In addition to paper submissions, the workshop featured a live and offline reasoner competition where standard reasoning tasks were tested:(More)
The SPARQL query language is currently being extended by the World Wide Web Consortium (W3C) with so-called entailment regimes. An entailment regime defines how queries are evaluated under more expressive semantics than SPARQL’s standard simple entailment, which is based on subgraph matching. The queries are very expressive since variables can occur within(More)
Ontology classification—the computation of subsumption hierarchies for classes and properties—is one of the most important tasks for OWL reasoners. Based on the algorithm by Shearer and Horrocks [9], we present a new classification procedure that addresses several open issues of the original algorithm, and that uses several novel optimisations in order to(More)
An important reasoning task, in addition to the standard DL reasoning services, is conjunctive query answering. In this paper, we present a decision procedure for conjunctive query entailment in the expressive Description Logic SHOQ. In particular, we present the first query entailment decision procedure for a logic that allows for nominals. We achieve this(More)
Ontological metamodeling has a variety of applications yet only very restricted forms are supported by OWL 2 directly. We propose a novel encoding scheme enabling class-based metamodeling inside the domain ontology with full reasoning support through standard OWL 2 reasoning systems. We demonstrate the usefulness of our method by applying it to the(More)
An important reasoning task, in addition to the standard DL reasoning services, is conjunctive query answering. In this paper, we present algorithms for conjunctive query answering in the expressive Description Logics SHQ and SHOQ. In particular, we allow for transitive (or nonsimple) roles in the query body, which is a feature that is not supported by(More)