nLab identity anafunctor

The identity anafunctor on a category $C$ is the anafunctor $id_C: C \to C$ that, as a span of functors, looks like $C \stackrel{id_C}\leftarrow C \stackrel{id_C}\rightarrow C$, where now $id_C$ is the identity functor on $C$. Of course, this is the same as the identity functor on $C$ interpreted as an anafunctor.

The identity anafunctors are the identities for composition of anafunctors in Cat.