A Four-Valued Fuzzy Propositional Logic

It is generally accepted that knowledge based systems ivouìd be smarter and more robust if they ean manage inconsistent. incomplete or imprecise knowledge. This paper is about a four-valued fuzzy propositionai logic, u-hich is thè result of thè combination of a fbur-valued logic and a fuzzy propositional logic. Beàides thè nice cornputational properties. thè logic en-ables us also to deal both with inconsistency and imprecise predicates in a simple way.