Author: Samuel Adrian Antz Format: MarkdownItexAdded list of low dimension manifolds and added $U(2)$ to the examples.
<a href="https://ncatlab.org/nlab/revision/diff/4-manifold/7">diff</a>, <a href="https://ncatlab.org/nlab/revision/4-manifold/7">v7</a>, <a href="https://ncatlab.org/nlab/show/4-manifold">current</a>
Added list of low dimension manifolds and added to the examples.