Title :
Normal forms of fuzzy middle and fuzzy contradictions
Author :
Turksen, I.B. ; Kandel, Abraham ; Zhang, Yan-Qing
Author_Institution :
Dept. of Mech. & Ind. Eng., Toronto Univ., Ont., Canada
fDate :
4/1/1999 12:00:00 AM
Abstract :
The expressions of “excluded middle” and “crisp contradiction” are reexamined starting with their original linguistic expressions which are first restated in propositional and then predicate forms. It is shown that, in order to generalize the truth tables and hence the normal forms, the membership assignments in predicate expressions must be separated from their truth qualification. In two-valued logic, there is no need to separate them from each other due to reductionist Aristotalean dichotomy. Whereas, in infinite (fuzzy) valued set and logic, the separation of membership assignments from their truth qualification forms the bases of a new reconstruction of the truth tables. The results obtained from these extended truth tables are reducible to their Boolean equivalents under the axioms of Boolean theory. Whereas, in fuzzy set and logic theory, we obtain a richer and more complex interpretations of the “fuzzy middle” and “fuzzy contradiction.”
Keywords :
Boolean algebra; fuzzy logic; logic design; multivalued logic; Boolean equivalents; Boolean theory; fuzzy contradiction; fuzzy contradictions; fuzzy middle; fuzzy set; linguistic expressions; logic theory; membership assignments; normal forms; predicate forms; truth tables; two-valued logic; Cognitive science; Computer science; Cost accounting; Fuzzy logic; Fuzzy set theory; Fuzzy sets; Industrial engineering; Natural languages; Qualifications; Set theory;
Journal_Title :
Systems, Man, and Cybernetics, Part B: Cybernetics, IEEE Transactions on
DOI :
10.1109/3477.752796