 U+220F ISOamsb --&gt;
&lt;!-- prod is NOT the same character as U+03A0 'greek capital letter pi' though
     the same glyph might be used for both --&gt;
&lt;!ENTITY sum      CDATA "&amp;#8721;" -- n-ary sumation, U+2211 ISOamsb --&gt;
&lt;!-- sum is NOT the same character as U+03A3 'greek capital letter sigma'
     though the same glyph might be used for both --&gt;
&lt;!ENTITY minus    CDATA "&amp;#8722;" -- minus sign, U+2212 ISOtech --&gt;
&lt;!ENTITY lowast   CDATA "&amp;#8727;" -- asterisk operator, 