How do i loop between two numbers

I have a list of documents and i want to know if a given document is missing.  I know the high and low numbers that SHOULD be there and want to compare that to what IS there (in the database). I want to create a loop where i set the low serial number and the high serial number and loop through those numbers to see if there is any missing by checking to see if if each number is in the database.     If there is a better way of doing this i’m missing it.  
1 answers

Use the activity ‘List operation’ → ‘ Intersect’

If the result is an empty list, then your object is not in the list.