erride</span> <span class="ci">ToString</span><span class="cp">:</span> <span class="ci">unit</span> <span class="cr">-&gt;</span> <span class="ci">string</span>

  <span class="ck">interface</span> <a href="https://msdn.microsoft.com/en-us/library/ms131187.aspx"><span class="ci">System</span><span class="cm">.</span><span class="ci">IEquatable</span></a><span class="cp">&lt;</span><span class="ci">Position</span><span class="cp">&gt;</span>
  <span class="ck">interface</span> <a href="https://msdn.microsof