This is part 16 of Categories for Programmers. Previously: The Yoneda Lemma. See the Table of Contents. We’ve seen previously that, when we fix an object a in the category C, the mapping C(a, _) is a (covariant) functor from C to Set. x -> C(a, x) (The codomain is Set because the hom-set C(a, […]![]()
