  type of <code class="computeroutput"><span class="identifier">b</span></code>, then the attribute
          type of <code class="computeroutput"><span class="identifier">a</span> <span class="special">&gt;&gt;</span>
          <span class="identifier">b</span></code> (<code class="computeroutput"><span class="identifier">a</span>
          <span class="special">&lt;&lt;</span> <span class="identifier">b</span></code>)
          will be <code class="computeroutput"><span class="identifier">tuple</span><spa