Fuzzy logic is a subset of a traditional type of logic called Boolean logic. Boolean logic is quantitative, distinguishing between truth and non-truth. Fuzzy logic, however, is a qualitative type of logic that is able to distinguish more than simple true and false values. It was introduced by Lotfi Zadeh of the University of California at Berkeley in the 1960's as a way to model the uncertainty of natural language.

Zadeh pursued a model that was imposing in program development, but was germane to everyday life. Vagueness and ambiguity are a part of everyday life. For example, the question, "Is it hot outside?" generates a variety of responses, based on the responder's experiences and knowledge. The question and the responses are both subjective. Abstract, subjective thought is a complex human thought process, and fuzzy logic has thus been compared to the human thought process.

Fuzzy logic...