DR, DEVICE: A Defeasible Logic RDF Rule Language

Rules and Rule Markup …, 2005

Defeasible reasoning is a rule-based approach for efficient reasoning with incomplete and inconsistent information. Such reasoning is useful for many applications in the Semantic Web, such as policies and business rules, agent brokering and negotiation, ontology and knowledge merging, etc., mainly due to interesting features, such as conflicting rules and priorities of rules. However, the RuleML syntax of defeasible logic may appear too complex for many users. Furthermore, the interplay between various technologies and languages, such as defeasible reasoning, RuleML, and RDF impose a demand for using multiple, diverse tools for building rule-based applications for the Semantic Web. In this paper we present VDR-Device, a visual integrated development environment for developing and using defeasible logic rule bases on top of RDF ontologies. VDR-Device integrates in a user-friendly graphical shell, a visual RuleML-compliant rule editor that constrains the allowed vocabulary through analysis of the input RDF ontologies and a defeasible reasoning system that processes RDF data and RDF Schema ontologies.

2012

The Semantic Web represents an initiative to improve the current Web, by augmenting content with semantics and encouraging cooperation among human and software agents. The development of the logic and proof layers of the Semantic Web is currently concentrating the related research effort and is vital, since these layers allow systems to infer new knowledge from existing information, assisting them in explaining their actions and, ultimately, increasing user trust towards the Semantic Web. However, there is a lack of applications that could contribute towards developing logic-based applications. Consequently, users resort to inadequate tools that offer syntactic support, without being able to support the user semantically as well. This work presents S 2 DRREd, a software tool that introduces a supplementary level of semantic assistance during rule base development. The tool allows creating meta-models of the main notions of the loaded rule sets and assists the user in authoring rule bases, independently of the explicitly chosen rule language syntax. The domain of application is defeasible logic, a type of logic that allows reasoning with incomplete and conflicting information and, as such, it can play an increasingly important role in a drastically dynamic environment like the Web.

Rules and Rule Markup Languages for the …, 2004

In this paper we present R-DEVICE, a deductive rule language for reasoning about RDF metadata. R-DEVICE includes features such as normal and generalized path expressions, stratified negation, aggregate, grouping, and sorting, functions. The rule language supports a second-order syntax, where variables can range over classes and properties. Users can define views which are materialized and, optionally, incrementally maintained by translating deductive rules into CLIPS production rules. Users can choose between an OPS5/CLIPS-like or a RuleML-like syntax. R-DEVICE is based on a OO RDF data model, different than the established graph model, which maps resources to objects and encapsulates properties inside resource objects, as traditional OO attributes. In this way, less joins are required to access the properties of a single resource resulting in better inferencing/querying performance. The descriptive semantics of RDF may call for dynamic re-definitions of resource classes and objects, which are handled by R-DEVICE effectively.

2009

The Semantic Web is a vision of the current Web where resources have exact meaning assigned in terms of ontologies, thus enabling agents to reason about them. As inconsistencies cannot be treated by standard reasoning approaches, we use Defeasible Logic Programming (DeLP) to reason with possibly inconsistent ontologies. In this article we show how to integrate rules and ontologies in the Semantic Web. We show how to use a possibly inconsistent set of rules represented by a DeLP program to reason on top of a set of (possibly inconsistent) ontologies.

Rules and Reasoning, 2017

The success of the Semantic Web highly depends on its ingredients. If we want to fully realize the vision of a machine-readable Web, it is crucial that Linked Data are actually useful for machines consuming them. On this background it is not surprising that (Linked) Data validation is an ongoing research topic in the community. However, most approaches so far either do not consider reasoning, and thereby miss the chance of detecting implicit constraint violations, or they base themselves on a combination of dierent formalisms, eg Description Logics combined with SPARQL. In this paper, we propose using Rule-Based Web Logics for RDF validation focusing on the concepts needed to support the most common validation constraints, such as Scoped Negation As Failure (SNAF), and the predicates dened in the Rule Interchange Format (RIF). We prove the feasibility of the approach by providing an implementation in Notation3 Logic. As such, we show that rule logic can cover both validation and reasoning if it is expressive enough.