Author: Urs Format: MarkdownItexa stub, for the moment just so as to make links work
<a href="https://ncatlab.org/nlab/revision/Spin%285%2C1%29/1">v1</a>, <a href="https://ncatlab.org/nlab/show/Spin%285%2C1%29">current</a>
a stub, for the moment just so as to make links work