Fuzzy Relation Equations with Words

In this paper, we focus on two questions. The first one is, how a systematic theory of the specific linguistic expressions widely used in the applications of fuzzy logic can be developed. These expressions form a class of the so called evaluating linguistic expressions. These are all expressions such as “small, very small, roughly medium, more or less big”, etc. and fuzzy numbers (also modified using linguistic hedges). Such a theory has been proposed in this paper. We argue that it fits well the meaning of the discussed expressions.