Semantic minimization of 3-valued propositional formulae

This paper presents an algorithm for a non-standard logic-minimization problem that arises in 3-valued propositional logic. The problem is motivated by the potential for obtaining better answers in applications that use 3-valued logic. An answer of 0 or 1 provides precise (definite) information; an answer of 1/2 provides imprecise (indefinite) information. By replacing a formula φ with a "better" formula ψ, we may improve the precision of the answers obtained. In this paper we give an algorithm that always produces a formula that is "best" (in a certain well-defined sense).