# What is Fuzzy logic and how does it help washing machines?

*Fuzzy logic is derived from fuzzy set theory dealing with reasoning that is approximate rather than precisely deduced from classical predicate logic. It can be thought of as the application side of fuzzy set theory dealing with well thought out real world expert values for a complex problem (Klir 1997). Degrees of truth are often confused with probabilities. However, they are conceptually distinct; fuzzy truth represents membership in vaguely defined sets, not likelihood of some event or condition. For example, if a 100ml glass contains 30ml of water, then, for two fuzzy sets, Empty and Full, one would probably define the glass as being 70% empty and 30% full. Note that the concept of emptiness would be subjective and thus would depend on the observer or designer. Another designer might equally well design a set membership function where the glass would be considered full for all values down to 50ml. A probabilistic setting would firstly define a scalar variable for the fullness of th