Defuzzification is an essential problem in fuzzy systems that it is always solved in a heuristic way. The aim of this work is to give a semantic interpretation to this process with the help of indistinguishability operators
Recasens, J.; Boixader, D.; Jacas, J. Searching for meaning on defuzzification. "International journal of uncertainty fuzziness and knowledge-based systems", Octubre 1999, vol. 7, núm. 5, p. 475-482.