a1 University of Amsterdam Email: email@example.com
a2 University of Utrecht Email: firstname.lastname@example.org
By establishing an appropriate equivalence, we observe that the theory of semi-functors can be fully embedded in the theory of (ordinary) functors. As a result, standard properties and constructions on functors extend automatically to semi-functors.
(Received May 17 1993)
(Revised March 28 1994)