 is forbidden</li>
</ul>

<p>
However when there is a solution and <b>Solution</b> is selected, the map changes to show information about that solution. In this case:
</p>

<ul class="org-ul">
<li>Red elements are in the network</li>
<li>Yellow elements are peripheral pipes, reachable by the network but not useful</li>
<li>Magenta elements are not reachable from any supply location, so could never be connected</li>
<li>Green elements have alternative heating systems selected (when the objective allows this)