An extension of PROLOG for object-oriented programming in logic

Abstract

In this paper, we attempt extending Logic Programming “smoothly” in order to allow object-orientation in a PROLOG-like environment. We call our extension “PROLoop” (Yet another PROLOG-based Language for Object-Oriented Programming). PROLoop is the essential component of a PROLOG-based environment (“PROViro”) to develop knowledge and rule-based expert systems. PROViro consists of a series of pragmatic components as to testing (PROTest), knowledge version control (PROVers), self actualization of the documentation (PROSelf), etc. The potential of PROLoop stems from its simplicity. This simplicity makes PROLoop easy to use and to extend, allows to achieve a high degree of reliability of PROLoop programs, increases their maintainability, etc. Because of its artlessness, PROLoop is also a good example for understanding and teaching object-oriented programming. Nevertheless, PROLoop possesses sufficient expression power which we demonstrate by including non-trivial examples produced in a real project.