In this paper, the fuzzy set [Zadeh (1965)] is viewed as a multivalued logic with a continuum of truth values in the interval [0, 1]. The concepts of in- consistency, validity, prime implicant and prime implicate are extended to fuzzy logic and various properties of these notions m the context of fuzzy logic are established. It is proved that a formula is valid (inconsistent) in fuzzy logic iff it is valid (inconsistent) in two-valued logic. An algorithm that generates fuzzy prime implicants (implicates) is introduced. A proof of the completeness of this algorithm is also given.