Nice, Simon! I thought

$\mathrm{Fun}^{\text{op}} = \mathrm{PainInTheButt}.$

By the way, we've been writing \$$\mathcal{B}^\mathcal{A}\$$ for the functor category you're calling \$$\mathrm{Fun}(\mathcal{A}, \mathcal{B})\$$. In case anyone here doesn't remember, I discussed functor categories here:

* [Lecture 41 - Chapter 3: Composing Natural Transformations](https://forum.azimuthproject.org/discussion/2249/lecture-45-chapter-3-composing-natural-transformations/p1).