 In general, it does not seem possible to solve the problem of future contingents in terms of three-valued semantics in a satisfactory manner if the logic is truth-functional, i.e., if the truth-value of any proposition used in the logic is determined by the truth-values of its parts. As argued by Prior (1953, p. 326) it will not help to change the truth-tables to something different from Łukasiewicz’s model. As long as the model or theory is truth-functional, it is obvious that the two disjunctions \((F(x)q \vee{\sim}F(x)q)\) and \((F(x)q \vee F(x)q)\) will have the same truth-value. From an intuitive and common sense point of view, this is not satisfactory, since \((F(x)q \vee{\sim}F(x)q)\) is clearly true, whereas \((F(x)q \vee F(x)q)\) is undetermined, given that \(F(x)q\) is undetermined.