User:Robertbyrne/End

Ends are universal constructs in category theory, a branch of mathematics. They are related to limits and Kan extensions.

In Categories for the Working Mathematician they are described as


 * "a special (and especially useful) type of limit, defined by universal wedges in place of universal cones."

=Definition= As with the other universal constructs in category theory, there are two kinds of ends, which are dual to one another.

End
The end of a functor $$F : \mathbf{A}^{\mathrm{op}} \times \mathbf{A} \rightarrow \mathbf{B}$$ is a universal dinatural transformation from

Coend
=References=
 * Mac Lane, S. (1998). Categories for the Working Mathematician. Second Edition. Springer-Verlag. ISBN 0-387-98403-8.