category
=======

Algebraic structures.

* [basic](basic.lean) : definition of fully and partially bundled categories
* [morphism](morphism.lean) : isos, retracts, sections, monos, epis
* [functor](functor.lean) : functors, category of (smaller) categories
* [natural_transformation](natural_transformation.lean)
* [constructions](constructions.lean) : constructions of basic examples and constructions of categories: opposite, type, discrete, product, functor, slice and arrow categories

The following files hardly have any content so far.

* [limit](limit.lean) : limits and colimits
* [adjoint](adjoint.lean) : adjoint functors
* [yoneda](yoneda.lean) : Yoneda embedding and Yoneda lemma