                            U+21D4 ISOamsa --&gt;

&lt;!-- Mathematical Operators --&gt;
&lt;!ENTITY forall   CDATA "&amp;#8704;" -- for all, U+2200 ISOtech --&gt;
&lt;!ENTITY part     CDATA "&amp;#8706;" -- partial differential, U+2202 ISOtech  --&gt;
&lt;!ENTITY exist    CDATA "&amp;#8707;" -- there exists, U+2203 ISOtech --&gt;
&lt;!ENTITY empty    CDATA "&amp;#8709;" -- empty set = null set = diameter,
                                     U+2205 ISOamso --&gt;
&lt;!ENTITY nabla    CDATA "&amp;#8711;" --