Author: nLab edit announcer Format: MarkdownItex$\sigma i = i\sigma$ is a natural transformation from $\sigma\sigma$ to $\sigma$ (if I am not mistaken).
Anonymous
<a href="https://ncatlab.org/nlab/revision/diff/radical/9">diff</a>, <a href="https://ncatlab.org/nlab/revision/radical/9">v9</a>, <a href="https://ncatlab.org/nlab/show/radical">current</a>
is a natural transformation from to (if I am not mistaken).