# Enchiridion: Vol. 3 (2017): Sarah Yeakel

Author
Sarah Yeakel (University of Maryland, College Park)

Source Paper
A monoidal model for Goodwillie derivatives
(arxiv:1706.06915)

Source Paper Abstract
Using the category of finite sets and injections, we construct a lax monoidal model for Goodwillie’s derivatives of a functor between spaces or spectra. Along the way, we show that the cross effects of a monad form a functor-operad. We also recover a chain rule for endofunctors of spaces, expressing the derivatives of the composite $F\circ G$ as a derived composition product of the derivatives of $F$ and $G$.