On NPN logic

It is argued that two-valued logic and fuzzy logic both lack some representational and reasoning capability in modeling directly a social or natural world with a combination of positive, negative, and neutral relationships. This is due to the fact that the logic values in both lie in the interval (0, 1). An NPN (negative-positive-neutral) crisp logic and an NPN fuzzy logic are presented that assume, respectively, crisp or fuzzy values in the interval (-1, 1). The notions of NPN relations and NPN heuristic transitive closures are introduced. It is suggested that NPN logics can be embedded into NPN relations for cognitive process modeling. An application is given to illustrate the theory.<>