The ROL deductive object base language

The paper presents a novel deductive object base language, called ROL (Rule-based Object Language), which has been implemented at the University of Regina (Canada) and is available via anonymous ftp. It effectively integrates important features of object oriented databases and deductive databases into a uniform framework. It supports object oriented features such as object identity, complex objects, classes, class hierarchy, multiple inheritance, and schema. It also supports structured values such as functor objects and sets, treats them as first class citizens, and provides powerful mechanisms for representing both partial and complete information on sets. It is an extension of pure valued oriented deductive languages such as Datalog and LDL (without grouping) and subsumes them as special cases. Furthermore, it has a logical semantics that cleanly accounts for all of its object oriented and value oriented features.