Tools of the fuzzy set theory in pattern recognition

The mathematical tools for patter recognition and classification are described which rely on the concepts of a fuzzy set and a linguistic variable. The approach is used in decision making under uncertainty; advice is made that the decision making procedure with a high number of patterns should be an inference rule which is an extension of the modus pannens rule to the case of fuzzy sets. For illustration determination of the aircraft kind from an arbitrarily specified number of features is given.