Operational semantics of an extension of ODRL able to express obligations

Nowadays economy is every day more and more a digital economy where many human activities are performed by means of digital devices. Those digital activities produce and operate on a big amount of digital assets, as the data stored in datasets, documents, images, videos or audio files. Rationally, it is useless that digital assets are made public without the specification of constrains on their usage and access. Many formal languages for expressing licenses, policies, norms, agreements, and contracts have been proposed in literature. Among them, the Open Digital Rights Language (ODRL) is a quite general one. In this paper, we present an extension of the syntax of ODRL for expressing conditional obligations. We present also an operational semantics of this extension with the goal of being able to perform automatic reasoning on the dynamic evolution in time of obligations. The definition of such operational semantics will be based on the specification of the lifecycle of obligations and on the definition of the mechanisms for computing their state using automatic reasoning. In particular, for doing that we use as far as possible, W3C standards: RDF and RDF Schema for the specification of obligations, and the Apache Jena general purpose rule engine for efficiently deducing the state of obligations on the bases of the state of the interaction among agents.