Archive for the ‘Category Theory’ Category

Fun With Representable Functors, or Why I Like Yondea’s Lemma.

Sunday, August 16th, 2009

We discuss the notion of representable functors in Category Theory. Then, we present Yoneda’s lemma and apply it to the situation of group objects in categories and their relation to functors into the category of groups, resulting in a surprising result that these two concepts are essentially the same. Most proofs are included, as well as lots of commutative diagrams.