The physiology of PROLOG expert system inference engine

The current literature on expert systems development in Prolog is replete with sample inference engines. However, the available models tend to be fragmentary and simplistic. Important issues such as how to incorporate arithmetic evaluation into the reasoning Process are often ignored. Therefore, we present and describe a more realistic Prolog expert system inference engine. The inference engine is an enhanced version of a standard model. It includes features and employs techniques that are non-existent in current models. We give special consideration to the relationship that the inference engine bears to the underlying Prolog engine. The role of unification and SLD resolution in the life of a Prolog expert system inference engine is also discussed.