Author: Tim_Porter Format: MarkdownItexAdded some comments and updated the table of contents a bit.
<a href="https://ncatlab.org/nlab/revision/diff/Crossed+Menagerie/17">diff</a>, <a href="https://ncatlab.org/nlab/revision/Crossed+Menagerie/17">v17</a>, <a href="https://ncatlab.org/nlab/show/Crossed+Menagerie">current</a>
Added some comments and updated the table of contents a bit.