Unable to fetch the Calculation Card (Timecards) union value in Oracle Payroll fast formula

Purpose is to fetch the Calculation Card (Timecards) union value in Oracle Payroll fast formula but this is not working and returning default value.

1) Defined Calculation  Value Definition 'TC Union NR'
2) Defined Payroll Calculation Information:  Calculation Factor 'Part Name'
3) Transfer Timecard to Payroll Calculation Card. 
4) Oracle Payroll Formula: "DT_UNION_EARN_RESULTS" using below syntax which is not working and returning default value 'XYZ'

 

CHANGE_CONTEXTS(PART_NAME = 'TC Union NR') 
(
        CALL_FORMULA('CALL_CALC_VALUE',
                  0 > 'BASE',
      l_union < 'CVD Union NR' DEFAULT 'XYZ'
                                           )
  )

 

Tried to get the value in 'l_union’, this is not working and returning default value xyz.