Yin - Yang equation in fuzzy logic is A = not A or Half glass of water = Half empty glass or 0 = 1.

Fuzzy logic washing machines, air conditioners, vacuum cleaners, antis kid brakes etc save energy/fuel/money. In auto engine (control fuel injection and ignition), auto transmission (selects gear, based on load), elevator control, traffic control, microwave oven, rice cooker (regulates steam temperature as per volume), auto focus in camera, cancels handheld filtering (shivering) in video camcoders, Television (auto colour, brightness and volume control), stopping a vehicle at a predetermined position, auto trouble shooter etc.

Software can produce a fuzzy logic system in minutes and the human brain has to tune it for real situations. Scientists are in search of developing a neural system, which can take our brains out of the loop and give fuzzy systems their own brain. Fuzzy engineers turn expert talk into fuzzy rules. An adaptive fuzzy system acts as a human expert.

Expert system consists of knowledge base and the inference engine. This uses black and white logic (0 and 1).