An extension of two-valued Logic such that statements need not be True or False, but may have a degree of truth between 0 and 1. Such a system can be extremely useful in designing control logic for real-world systems such as elevators.
See also Alethic, False, Logic, True
References
Fuzzy Logic
McNeill, D. and Freiberger, P. Fuzzy Logic: The Discovery of a Revolutionary Computer Technology and How It is Changing Our World.
Nguyen, H. T. and Walker, E. A. A First Course in Fuzzy Logic. Boca Raton, FL: CRC Press, 1996.
Yager, R. R. and Zadeh, L. A. (Eds.) An Introduction to Fuzzy Logic Applications in Intelligent Systems.
Boston, MA: Kluwer, 1992.
Zadeh, L. and Kacprzyk, J. (Eds.). Fuzzy Logic for the Management of Uncertainty. New York: Wiley, 1992.