Odissea: a language for deductlve information systems

In this paper we describe the ODISSEA language for the specification of information systems defined in the deductive approach. This language is being developed as part of the ODISSEA project, which aims at exploring the issues involved in the specification, design, construction, mantenance and evolution of what we call Deductive Information Systems. The sentences of the language are explained in detail with the aid of an example. We also give the complete BNF definition of the language. Finally, there is a brief explanation of the ODISSEA project and its execution and development environments.