===== Constant functor =====
==== Functor ====
| @#55CCEE: context     | @#55CCEE: ${\bf C},{\bf D}$ ... category |
| @#55CCEE: context     | @#55CCEE: $D:\mathrm{Ob}_{\bf D}$ |
| @#FFBB00: definiendum | @#FFBB00: $\Delta_D:{\bf C}\longrightarrow{\bf D}$ |
| @#FF9944: definition  | @#FF9944: $\Delta_DC:=D$ |
| @#FF9944: definition  | @#FF9944: $\Delta_D(f):=\mathrm{id}_D$ |

==== Discussion ====
=== Reference ===
Wikipedia: [[http://en.wikipedia.org/wiki/Diagonal_functor|Diagonal functor]]

nLab: [[http://ncatlab.org/nlab/show/constant+functor|constant functor]]

==== Parents ====
=== Element of ===
[[Functor]]