Hello Rodrigo,
Rule ZEXF seems to have been created to process only WTs 1840 and 1845, and these WTs will be processes regardless of what ESG they have in the Input Table (if the pcr is called by Function PIT) or in the Results Table (if the pcr is called by Function PRT). Both WTs have very similar processing, so I will explain only processing of WT 1840.
The first Operation is PRINT&LIEI and that would enable you to be able to see the value of the Temporary Variable LIEI in the Payroll Log, but it does not modify the WT being processed.
The second Operation is AMT?& LIEI and that will compare the Amount of WT 1840 (from the Input Table) to the Amount of the Temporary Variable.
If the return value is Greater Than (>), then it will replace the Amount of WT 1840 by the Amount of the Temporary Variable, and the resulting Rate, Number and Amount will be used to create WT 9E50 in the Results Table, to create WT 9G50 with negative values in the Results Table, and to substract it's values from the values of the Temporary Variable LIEL.
If the return value is "Other" (*), then the Rate, Number and Amount of WT 1840 will be used to create WT 9E50 in the Results Table, to create WT 9G50 with negative values in the Results Table, and to substract it's values from the values of the Temporary Variable LIEL.
Note that in both cases, WT 1840 will "disappear" from the Input Table.
If you do a Payroll Simulation for one employee, with the "Display log" box checked, drill down into your log until you find pcr ZEXF, and double-clic on it, you should be able to see the Input Table (with WTs 1840 and 1845), the processing (including the value of the Temporary Variable LIEL), and note the differences in the output. If after pcr ZEXF you add Function PRINT with Par2 = Var, you would be able to also see the value of the temporary variables after the processing.