Use Get ( RecordNumber ) to return the current record's position in the found set.
Use GetNthRecord to refer to a field in the previous record.
Let ( R = Get ( RecordNumber ) ; If ( R = 1 ; True ; FieldName ≠ GetNthRecord ( FieldName ; R - 1 ) ) )
Unfortunately that is where the inconsistant field names come in. They are not always sequential, skip numbers, and sometimes use decimal values. Would there be anyway to use LookupNext Higher/lower? Or perhaps a formula that would subtract R - .001 and then round down to the next lowest value?
Get (RecordNumber) does not return serial number or recordID values. It returns the record's position in the found set's sort order. These are always whole numbers and skipped values are not an issue.
Say you have 5 records in your current found set. If you are on the first record, Get ( RecordNumber ) returns 1. If you are on the second record, Get ( RecordNumber ) returns 2 and so forth on to 5 for the last record. If you sort your records in a new order, Get ( RecordNumber ) from the first record still returns 1.