 Establish some helpful LaTeX shortcuts for equations -->
<div class="section level2">
<h2 id="introduction">Introduction<a class="anchor" aria-label="anchor" href="#introduction"></a>
</h2>
<p>Matrices are important mathematical objects, and they often describe
networks of flows among nodes. Example networks are given in the
following table.</p>
<table class="table">
<thead><tr class="header">
<th align="left">System type</th>
<th align="left">Flows</th>
<th align="left">Nodes</th>
</tr></thead>
<tbody>
<t