Two-sided (intuitionistic) fuzzy reasoning

Fuzzy prepositional logic structure is summarized; different forms of fuzzy prepositional expressions and their relations are discussed. Two-sided fuzzy proposition is defined in prepositional logic algebra as the counterpart of intuitionistic fuzzy set. The concept of two-sided fuzzy reasoning is discussed and its mathematical structure is developed. Using two-sided fuzzy propositions, human decision making can be closely simulated by considering his perception of both (somewhat opposite) sides of the subject matter simultaneously. Multiuniverse two-sided fuzzy propositions are presented and multiuniverse operations are defined. Two-sided fuzzy if-then rules are investigated under different interpretations of fuzzy implications. Approximate of these different implications and the inferences in the output universe are investigated, and associated error terms are identified.