Sequences are a natural part of the world to be modelled in ontologies. Yet the Web Ontology Language, OWL, contains no specific support for ordering. It does, however, have constructs that can be used to model many aspects of sequences, albeit imperfectly. This paper demonstrates a design pattern for modeling order within OWL-DL. This allows us to use standard DL reasoning to perform pattern m...

OWL DL puts several constraints on the possibilities to talk about the elements of an ontology. In particular, it is not possible to make statements about the axioms of an ontology or to make higher-order statements about the classes and properties of an ontology. This lack of expressiveness may cause problems throughout the whole lifecycle of an ontology, and especially in its practical usage....

Answering (conjunctive) queries is an important reasoning task in Description Logics (DL), hence also in highly expressive ontology languages, such as OWL. Extending such ontology languages with rules, such as those expressible in RIF-Core, and further with non-monotonic rules, integrating default negation as described in the RIF-FLD, yields an even more expressive language that allows for mode...

Ontology languages like OWL allow for semantically rich annotation of resources, such as products advertised at an electronic online marketplace, while the Description Logic (DL) formalism underlying OWL provides reasoning techniques to perform matchmaking on such annotations. We identify peculiarities in the use of DL inferences for matchmaking which are due to the open-world semantics of OWL,...

ORE 2015, as previous years, also included a competition in which OWL reasoners were faced with different reasoning tasks. The competition included six disciplines in which reasoners could compete: ontology classification, consistency checking, and realisation each for the OWL 2 EL and OWL 2 DL profiles. The tasks were performed on several large corpora of real-life OWL ontologies obtained from...

Probabilistic OWL (PR-OWL) improves the Web Ontology Language (OWL) with the ability to treat uncertainty using Multi-Entity Bayesian Networks (MEBN). PR-OWL 2 presents a better integration with OWL and its underlying logic, allowing the creation of ontologies with probabilistic and deterministic parts. However, there are scalability problems since PR-OWL 2 is built upon OWL 2 DL which is a ver...

The CEL system is known for its scalability of reasoning in the lightweight DL EL which has been proved suitable for several ontology applications, most notably from the life science domain. Recently, the DL EL has been adopted as the logical underpinning of the OWL 2 EL profile of the new Web Ontology Language which potentially attracts new folks of CEL’s users. To seamlessly integrate the rea...

Although OWL is rather expressive, it has a very serious limitation on datatypes; i.e., it does not support customised datatypes. It has been pointed out that many potential users will not adopt OWL unless this limitation is overcome, and the W3C Semantic Web Best Practices and Development Working Group has set up a task force to address this issue. This paper makes the following two contributi...

The Semantic Web Rules Language (SWRL) has recently been proposed as the basic rules language for the Semantic Web. SWRL is unusual in being an undecidable superset of a very expressive description logic OWL DL (SHOIN (D)) and a simple rules language, Datalog. In this paper, we attempt to evolve OWL DL toward SWRL, but cautiously and carefully. We strive to retain practical decidability. We see...

We present the method developed for migrating the Foundational Model of Anatomy (FMA) from its representation with frames in Protégé to its logical representation in OWL and our experience in reasoning with it. Despite the extensive use of metaclasses in Protégé, it proved possible to convert the FMA from Protégé into OWL DL, while capturing most of its original features. The conversion relies ...