Abstract: In this paper, the uncertainty problems with regard to fuzzy truth value in fuzzy rules are investigated in depth. First, the different meaning of six propositions is completely analyzed. Next, a new logic combination relation, the generalized logic relation, is proposed in accordance with actual conditions of fuzzy rule application. Finally, the fuzzy sets matching degree and the fuzzy rule matching degree are defined and the inference algorithm of condition truth value and result truth value is presented, and the generalized uncertainty inference model is formed.

Key words: truth value, match, fuzzy rule, uncertainty inference