Reproving the basic principles of fuzzy sets for the decisions

Principles in the logic and the sets form the basis of many societal solutions that are present with physical as well as non-physical phenomena. Non-physical phenomena, for example present language variables that require the presence of the fuzzy logic and the fuzzy sets. Although specific verification of the rules used remains the same, the systematic verification for the fuzzy sets requires a strategy, including when implementing it into a computer program. The final problem has the answer to the change in the operator implemented in the program. (paper)