 it be, for symmetry?
     It is in ISOamsn  --&gt; 
&lt;!ENTITY nsub     CDATA "&amp;#8836;" -- not a subset of, U+2284 ISOamsn --&gt;
&lt;!ENTITY sube     CDATA "&amp;#8838;" -- subset of or equal to, U+2286 ISOtech --&gt;
&lt;!ENTITY supe     CDATA "&amp;#8839;" -- superset of or equal to,
                                     U+2287 ISOtech --&gt;
&lt;!ENTITY oplus    CDATA "&amp;#8853;" -- circled plus = direct sum,
                                     U+2295 ISOamsb --&gt;
&lt;!ENTITY otimes   CDATA "&