A six-valued logic for representing incomplete knowledge

A novel six-valued logic useful in representing incomplete knowledge is introduced. A practical advantage of this logic is that it allows a system to reason progressively about what it will or will not know (or what can or cannot happen) as time advances and further knowledge is acquired from the external world. Applications of this approach to deductive question-answering systems, as well as to decision-making and planning under time constraints, are investigated. A rule-based inference model based on the six valued logic has been built for this purpose. The results of this research indicate that an extension of the classical definition of modus ponens based on designated truth values would be a useful rule of inference