span class="keyword">using </span><a class="code hl_typedef" href="namespacenetdem.html#ad38442e20f0a9c4e248bca3f93b4c712">Mat2d</a> = std::array&lt;std::array&lt;double, 2&gt;, 2&gt;;</div>
<div class="line"><a id="l00022" name="l00022"></a><span class="lineno"><a class="line" href="namespacenetdem.html#a12a99007be78b9a11905e371fa21be78">   22</a></span><span class="keyword">using </span><a class="code hl_typedef" href="namespacenetdem.html#a12a99007be78b9a11905e371fa21be78">Mat3d</a> = std::array&lt;std::