Author: Urs Format: MarkdownItexadded some content to this old entry
<a href="https://ncatlab.org/nlab/revision/diff/Paul+Melvin/2">diff</a>, <a href="https://ncatlab.org/nlab/revision/Paul+Melvin/2">v2</a>, <a href="https://ncatlab.org/nlab/show/Paul+Melvin">current</a>