Classical logic is usually associated with the name of Aristotle and is strictly binary (a statement is either false or true). Fuzzy logic, initiated by L. A. Zadeh (1921-2017), makes use of all the gradations of gray, intermediate between white = false and black = true, and has proved extremely successful in building intelligent machines and industrial plants, ranging from simple household appliances to complex subway networks. The inferential makinery of fuzzy control, used to make suitable decisions, is a bold generalization of the classical syllogism called modus ponens. This article will deal with this topic.
