Performing Approximate Reasoning with Words?

When defining a term set as a (mite family of fuzzy sets on a universe of discourse, two description levels are introduced: the level of the referential and the level corresponding to the symbolic term set. Depending on the level which is privileged, two different views of reasoning with fuzzy set labels can be thought of: Zadeh’s view of approximate reasoning which takes place at the level of the universe of discourse, and another view where fuzzy sets are manipulated in a more symbolic way at the term set level, which would corresponds to the idea of computing with words recently advocated by Zadeh also. The two views are contrasted in this paper, and their differences are laid bare.