Hedge Algebras: an Algebraic Approach to Structure of Sets of Linguistic Truth Values

It is shown that any sets of linguistic values of linguistic variables can be axiomatized, which leads to a notion of hedge algebras. Some intuitive properties of linguistic hedges, which are a basis of the axiomatization of the hedge algebras, are discussed informally. The characteristics of the hedge algebras depend on such a discussion and they seem to reflect the natural structure of sets of linguistic values of linguistic variables. Some fundamental properties of hedge algebras are examined. They constitute a foundation of further development of our theory of hedge algebras and of some kind of fuzzy logic.