One of the ways to use a recursive function is to build a list and then test to see if a specific value exists in that list. To determine if a value exists in the list, the following method is usefull:
1. Build a calculation field that builds a list with the custom recursive function.
2. Build a calculation field or know the field that contains the value you need to test for.
3. Build a custom function as follows:
Parameters: checkList, checkValue
not IsEmpty( checkList ) and Position ( ¶ & checkList & ¶ ; ¶ & checkValue & ¶; 1 ; 1 ) > 0
4. Build a field that uses the custom function you just created. For the paramters of the custom function, use the calc field that you created in step 1 above for the “chekList” parameter and the calc field that you created in step 2 above for the “checkValue” paramter.
You can now determine whether a dynamically occurring value or static value exists in a dynamically changing group of records.