The fuzzy behaviour of preference tries to introduce indivi- duals whose preferences are not necessarily clear or coher- ent. The agents who have imprecise preferences are much more shaded. On the contrary of Boolean agents, fuzzy agents can- not decide anything with their only preferences....

Fuzzy set theory, which started not much more than 20 years ago as a generalization of classical set theory, has in the meantime evolved into an area which scientifically, as well as from the point of view of applications, is recognized as a very valuable contribution to the existing knowledge....