Object oriented and relational specification of information systems

Taking a Deductive and an Object Oriented approach to specify Information Systems has become a rich research topic. Within this framework, RMOL [11] and its active evolution OASIS [13] [9] are two object- oriented specification languages that provide a clausal expresiveness for dealing with open and passive/active Information Systems, integrating an objectual and a clausal logic from the specification sake, and keeping an efficient and well-defined operational semantics by SLDNF-resolution for prototyping. A weak point of RMOL was that its clausal expresiveness was restricted to normal clauses (those composed by literals, possitive or negative), loosing the full expressive power of general first order formulas. This paper presents an enhanced RMOL version allowing to use program statements [8] without restrictions. A full first order expresiveness has been added to the clausal and objectual Specification Language (SL). The Deductive Data Base (DDB) field is reached by accomodating the first order theory equivalent to the specification (represented as a logic program in Prolog) to the input required by the DDB prototype presented in (4]. An envi ronment composed of a set of Software too ls has been bu i l t, wi th the coomon objective of using formal specification techniques based on clausal and objectual logics, their fusions and extensions, providing a higher expresiveness without loosing a well defined declarative and efficient operational semantics. With these techniques, the validation of software by automatic prototyping is guaranteed, and furthermore, they allow to approach topics such as consistency, completeness etc. in a formalized framework. They also allow to deal with System Dynamics animating the DDB prototype resulting from the specification