ectional</span><span class="p">(</span><span class="n">Named</span><span class="p">):</span>
  <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">  Base class for derived Coord and Ax classes, representing &quot;direction&quot; (e.g. &quot;latitude&quot; or &quot;depth&quot;).</span>

<span class="sd">  An abstract equivalence relationship is defined among Directional objects where two objects are equivalent when they have the same &#39;associative&#39; attribute (pointing to an Associative object)