Fuzzy logic has successfully established itself as an engineering tool. Though its purpose and validity in any context were highly controversial in the early years, this initial criticism was defused by the practical success of fuzzy set theory, to a large degree under the name of "fuzzy logic". This began with Assilian's and Mamdani's steam engine in the 1970s [22] and has extended over an ever-expanding range of applications, from noodle cookers to washing machines, up to the present day. The history of fuzzy set theory's birth, development and progression has been documented by Rudolf Seising in his book The Fuzzification of Systems [32].