Index: doc/src/sgml/ddl.sgml
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RCS file: /cvsroot/pgsql/doc/src/sgml/ddl.sgml,v
retrieving revision 1.91
diff -c -c -r1.91 ddl.sgml
*** doc/src/sgml/ddl.sgml	1 Apr 2010 01:18:17 -0000	1.91
--- doc/src/sgml/ddl.sgml	6 Apr 2010 02:13:57 -0000
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*** 861,867 ****
     <para>
      Exclusion constraints ensure that if any two rows are compared on
      the specified columns or expressions using the specified operators,
!     at least one of these operator comparisons will be false. The syntax is:
  <programlisting>
  CREATE TABLE circles (
      c circle,
--- 861,868 ----
     <para>
      Exclusion constraints ensure that if any two rows are compared on
      the specified columns or expressions using the specified operators,
!     at least one of these operator comparisons will return false or null.
!     The syntax is:
  <programlisting>
  CREATE TABLE circles (
      c circle,