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- What is category theory useful for? 4 answers
I know the definition of a category and know several examples. But I have not studied the theory of categories.
Much of mathematics I studied can be written as a category and a functor.
But for me, a category is just an organizational language. What is the merit of studying category theory?
What can I obtain by reading Mac Lane's book?
Is it necessary to learn category theory to be a good mathematician, especially for number theorists, algebraists, and topologists?