Although Fuzzy Preorders and Fuzzy Equivalences are well established types of fuzzy relations, they are defined in terms of properties to be fulfilled in a crisp way. In this paper we relax those requirements by making them gradual in some way. As a result, a number of relations which are not strictly reflexive, symmetric or transitive with respect to any t-norm T, would be regarded as (Approximate) Fuzzy Preorders or Equivalences.
Boixader, D.; Recasens, J. Approximate fuzzy preorders and equivalences. A: IEEE International Conference on Fuzzy Systems. "Proceedings of the FUZZ-IEEE2009 International Conference on Fuzzy Systems". Jeju Island: 2009.
Group of research
FM&AI - Functional Mathematical Modelling and Applications