Relational       Value
          Operator
    -------------------------------------------------------------
          EQ        =      True if the two value expressions are
                           equal.
          NE        <>     True if the two value expressions are
                           not equal.
          GT        >      True if the first value expression is
                           greater than the second.
          GE        >=     True if the first value expression is
                           greater than or equal to the second.
          LT        <      True if the first value expression is
                           less than the second.
          LE        <=     True if the first value expression is
                           less than or equal to the second.
    -------------------------------------------------------------
         Note:   In all cases, if either value expression is
                 missing, the value of the condition is missing.