A 2-functor can be contravariant in three ways, depending on whether it reverses the 1-morphisms, the 2-morphisms, or both; this corresponds to the three kinds of opposite 2-category. All kinds of contravariant 2-functor appear in a 3-category with contravariance.
Created on June 17, 2016 at 18:16:23. See the history of this page for a list of all contributions to it.