Natural equivalences

Q:Why did the authors named the paper:"natural equivalence"? What is natural about the kind of equivalence they talked about in this paper?

A:The authors named the paper "natural equivalence" because the type of equivalence they describe is a fundamental and intrinsic property of the mathematical objects and morphisms in a category.

In category theory, a natural equivalence is a special type of equivalence that arises naturally from the structure of the category. Natural equivalences preserve the structure of the category in a particularly strong way, meaning that they are compatible with all functors and transformations in the category.

The authors of "The General Theory of Equivalence" describe natural equivalence as a generalization of the notion of equality for mathematical objects, allowing for the comparison of objects and morphisms in different categories. They show that natural equivalences can be used to relate different mathematical structures and to establish the equivalence of categories.

The authors use the term "natural" to emphasize the intrinsic and fundamental nature of the equivalence relationships described in the paper. Natural equivalences are not arbitrary or imposed, but rather arise naturally from the structure of the category itself. By describing natural equivalences, the authors provide a framework for understanding and comparing different mathematical structures in a more general and abstract way.

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