- #1
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This thing still confuses me. And it seems every reference I look at states it entirely differently. ![Frown :frown: :frown:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I guess I've heard it stated in words -- there is a full embedding of C in Funct(Cop, Set). I know what all of the words mean, but I'm not sure if that helps yet.![Smile :smile: :smile:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
There's one particular application of it that interests me, and I can't really see how to use it: there's a proof that shows the existence of a natural transformation Hom(_, A) --> Hom(_, B).
From this, they then conclude (by the Yoneda lemma!) that this natural transformation must come from a uniquely determined map A --> B. (The existence of this map is what interests me)
How does that follow?
I guess I've heard it stated in words -- there is a full embedding of C in Funct(Cop, Set). I know what all of the words mean, but I'm not sure if that helps yet.
There's one particular application of it that interests me, and I can't really see how to use it: there's a proof that shows the existence of a natural transformation Hom(_, A) --> Hom(_, B).
From this, they then conclude (by the Yoneda lemma!) that this natural transformation must come from a uniquely determined map A --> B. (The existence of this map is what interests me)
How does that follow?