Hello, the most difficult mathematics field is generally considered as fuzzy mathematics, which is a branch of mathematics that studies how to express and deal with fuzzy phenomena and get appropriate and accurate conclusions; Vagueness is a common phenomenon, which people always avoided in the past. However, due to the increasingly complex system faced by modern science and technology, fuzziness always appears with complexity. If you want a computer to have the ability to recognize complex things like a human brain, you must study and deal with fuzziness. It is the requirement of historical development to expand from classical set theory to fuzzy set. However, fuzzy mathematics is still immature and widely used. Its most important application field is computer intelligence, which has been applied to expert systems and knowledge. It can be seen that the study of fuzzy mathematics is still difficult.

I wish you a happy study.