Artificial Intelligence Applications are becoming crucial for enterprises that want to be successful by having the advantage of using high information technology. The development of such applications is assisted by the use of high level computer programming languages that are closer to the programmer than to the computer. Such a programming language is Prolog. Prolog is a logic programming language (Clocksin & Mellish 2003) that was invented by Alain Colmerauer and Phillipe Roussel at the University of Aix-Marseille in 1971. The name Prolog comes from programmation en logique (i.e., “programming in logic” in French). Together with LISP, they are the most popular Artificial Intelligence programming languages. Prolog was generated by an attempt to develop a programming language that extensively uses expressions of logic instead of developing a program by providing a specific sequence of instructions to the computer. Theoretically, it is based on a subset of first-order predicate calculus that allows only Horn clauses (Bratko, 2000). The control of the program execution is based on Prolog’s built-in search mechanism that in fact is an application of theorem proving by first-order resolution.
