able2&lt;T, U&gt;</code></td>

        <td><code>T operator-(const T&amp;, const U&amp;)</code></td>

        <td><code>T temp(t); temp -= u</code>.<br>
         Return convertible to <code>T</code>. See the <a href=
        "#symmetry">Symmetry Note</a>.</td>
      </tr>

      <tr>
        <td><code><a name="subtractable2_left">subtractable2_left&lt;T,
        U&gt;</a></code></td>

        <td><code>T operator-(const U&amp;, const T&amp;)</code></td>

        <td><code>T temp(u); temp -= t</code>.<br>
  