Comparing multiple PDF documents using R

#1
Is there a way to compare more than two or atleast two documents using R to identify the differences/common content?

I have about 60 PDF files at most one or two pages each that have similar content (but not the same). Some may be same. Each PDF is like an schedule/invoice kind of a document with line items (not paragraphs or anything). I'd like to compare to see which one are same and which ones aren't and the ones that aren't where the differences are.

e.g. one document may have a line item "Total balance of Account B" and another document may have "Total balance for sub-account C". In this case, the line items are similar but not the same so I'd like for R to highlight that the difference is after the word balance.
 

trinker

ggplot2orBust
#3
It could be done but I agree it may be very slow. THe tm package has a pdf reader as does one of the openScience packages on GitHub I believe