TOPIC 7.1.1
Fuzzy Logic is used to represent imprecise, ambiguous, or vague information. It is used to perform operations on concepts that are outside the definitions of boolean logic. It is a superset of conventional boolean logic that has been extended to handle intermediate values between "completely true" and "completely false". It was introduced by Dr. Lotfi Zadeh, a professor at the University of California in Berkeley in 1965, as a means to model the uncertainty of the real world.
An excellent introductory article is:
Bezdek, James C, "Fuzzy Models --- What Are They, and Why?", IEEE Transactions on Fuzzy Systems, 1:1, pp. 1-6, 1993.
For more information consult the following links:
Also see Boolean Algebra (On the Net Topic 4.1.4) for related information.