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Re:Programming with Categories by Twisol on Wednesday September 02, 2020 @08:00PM (#24359568)
More or less. "Morphism" is defined by the category it lives in, so a functor is a morphism between categories in the category of (small) categories. (Insert technicalities about size concerns and Russell's paradox.)

In particular, a map between categories that does not preserve composition is not a functor. It is important that F(f;g) = F(f);F(g).

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