Author: Tim_Porter Format: MarkdownItexAdded a link to his Cahiers paper from 2002.
<a href="https://ncatlab.org/nlab/revision/diff/Bertrand+To%C3%ABn/16">diff</a>, <a href="https://ncatlab.org/nlab/revision/Bertrand+To%C3%ABn/16">v16</a>, <a href="https://ncatlab.org/nlab/show/Bertrand+To%C3%ABn">current</a>