doc fix

I think this is right..

Patrick

Index: sql.sgml
===================================================================
RCS file: /projects/cvsroot/pgsql/doc/src/sgml/sql.sgml,v
retrieving revision 1.24
diff -p -r1.24 sql.sgml
*** sql.sgml    2001/10/23 16:42:36    1.24
--- sql.sgml    2002/02/11 15:37:47
*************** attributes are taken from. We often writ
*** 488,494 ****

        <listitem>
         <para>
!     DIFFERENCE (− or ∖): builds the set difference of
      two tables. Let <classname>R</classname> and <classname>S</classname>
      again be two tables with the same
      arity. <classname>R</classname> - <classname>S</classname>
--- 488,494 ----

        <listitem>
         <para>
!     EXCEPT (− or ∖): builds the set difference of
      two tables. Let <classname>R</classname> and <classname>S</classname>
      again be two tables with the same
      arity. <classname>R</classname> - <classname>S</classname>