terminal object

terminal object (plural terminal objects)

1. (category theory) An object within a category which receives arrows from all other objects in that category, and such that each of these arrows is unique.

   In the category of sets, a terminal object is any singleton, since there exists a unique function, namely the constant function, from any given set into that singleton.

   The terminal object is the limit over the empty diagram.

• initial object

• limit

• null object = zero object