Category Theory to Yoneda's Lemma

Greg O’Keefe 🌐

April 21, 2005

This is a development version of this entry. It might change over time and is not stable. Please refer to release versions for citations.


This development proves Yoneda's lemma and aims to be readable by humans. It only defines what is needed for the lemma: categories, functors and natural transformations. Limits, adjunctions and other important concepts are not included.


GNU Lesser General Public License (LGPL)


April 23, 2010
The definition of the constant equinumerous was slightly too weak in the original submission and has been fixed in revision 8c2b5b3c995f.


Session Category