PROLOG is a logical programming language used in the field of artificial intelligence. Alain Colmerauer invented Prolog in the early ’70s and David Warren from the University of Edinburgh implemented a compiler. French computer scientists Alain Colmerauer and Philippe Roussel were the people responsible for the initial creation of Prolog at the University of Marseilles, France in the 1970s. The name PROLOG was suggested by Phillipe’s wife Jacqueline as an abbreviation of ‘PROgrammation en LOGique’. As per by an article from Alain Colmerauer and Philippe Roussel, “The programming language Prolog was born of a project aimed not producing a programming language but at processing natural languages, in this case, French; the project gave rise to a preliminary version of prologue of the end of 1971 and the more definitive version of the end of 1972.”
In prolog, logic is expressed as relations as Facts and Rules. A prolog program consists of a set of facts and a set of rules. There are no type declarations, initializations.