fuzzy closed set

例句：

1. 1.The fuzzy set theory is a branchof mathematics that deals with thestudy of fuzzy sets.
   模糊集合理论是数学的一个分支，研究模糊集合。
2. 2.Fuzzy sets are used in many applicationssuch as image processing and pattern recognition.
   模糊集合在许多应用中被使用，如图像处理和模式识别。
3. 3. The fuzzy set theory has been applied to solvesome practical problems in engineering.
   模糊集合理论已被应用于解决工程中的一些实际问题。