�t change the position of the stream and returns <code class="fsharp"><span
      class="cb">false</span></code>. Thus, if the string is skipped, the parser returns with a <code class="fsharp"><a
      href="../reference/reply.html"><span class="ci">Reply</span></a></code> value containing the result (<span class="i">line 6</span>). Otherwise,
      it returns a <code class="fsharp"><a href="../reference/reply.html"><span class="ci">Reply</span></a></code> with the preconstructed error
      message (<span 