Understanding constructions in categories

This is an experiment. As with any experiment, it may flop.

The idea is to create a series of “Understandings”, i.e. tutorial references that work through category-theoretic constructions for various categories. Hopefully, each Understanding will be fairly homogeneous in structure, e.g. we define the category briefly with a reference to its formal page and then proceed to work through specific constructions in gory detail with specific examples.

These pages are to be friendly in nature with a similar spirit as John Baez’ This Week’s Finds in Mathematical Physics.

Here is a list of pages we hope to get started on:

Here is an initial list of constructions to include (originally designed for Set):

Under limits:

- terminal object
- binary products
- arbitrary (but small) products
- equalisers
- pullbacks
- fibred products

Under colimits:

- coterminal object
- binary coproducts
- arbitrary (but small) coproducts
- coequalisers
- pushouts
- cofibred coproducts

Other constructions:

- exponential objects
- dependent products
- power objects
- probably more

category: reference

Revised on October 9, 2010 14:59:14
by Eric Forgy
(219.78.39.176)