• XSB; the logic programming system that we use as the Reasoning Engine of our system
• SWI-Prolog; the system that we used to build to RDF(S)&OWL Translator. This module is used to translate RDF(S) and OWL information into logical facts and rules.

You can use the system in the following way: You can write your rules, either following the syntax of defeasible logic, in a text file, e.g. "rules.txt" or using the RuleML syntax in an xml file, eg "rules.xml". Your data can be expressed as facts in the defeasible logic syntax (so you can add them in the same rules' file), or in rdf; in the latter case, you can put them in an rdf file, e.g. "Instances.rdf". Put your rdfs/owl data describing the ontology schema in an rdfs file, e.g. 'schema.rdfs'. By using the system you can reason about the data using the rules in your rules' file. Specifically, you can ask the system to find the conclusions derived from the data and rules that you defined. Below, you can see the overall architecture of DR-Prolog.

Figure: The overall architecture of DR-Prolog.

You can download the zip file containing the source code for DR-Prolog. There you can find instructions on how to run DR-Prolog in the readme files. For any comments or questions about how to run DR-Prolog, you can contact Antonis Bikakis.