关键词: 计量逻辑学, 模糊度, 近似推理, 真度

Abstract: From the view whether it is easy to judge a formula correctly or not, this paper proposes the concept of fuzzy degree of a given formula in classical two-valued logic, which uses the numbers of a propositional logic assignment 1 and 0. This paper gives the related properties of fuzzy degree, and points out the connections and differences between fuzzy degree and the definition of truth degree in quantitative logic. The following conclusions are got: (1) In a reasoning process, with the lower of the fuzzy degree of premise, the fuzzy degree of conclusion is also lower; (2) The set which constitutes of the same fuzzy degree proposition formulas is inconsistent; (3) If the distance of two formulas is closer, the fuzzy degree of two formulas is closer.

Key words: quantitative logic, fuzzy degree, approximate reasoning, truth degree