1. If you run the 32-bit version of checker3 on a proof file over 4 GB,
   it does not notice the file is too large and dies with a seg fault.
   Ideally it would give an error message instead.
   It is necessary to use the 64-bit version of checker3 on proof files
   over 4 GB and actually the cutoff is a little lower, maybe 3.5 GB.

2. rupToRes makes mistakes on cnf files containing tautologous clauses.
   You can detect that a file had tautologous clauses by noticing that
   the clause count reported by rupToRes is less than the actual number
   of clauses.  checker3 reports that the proof file produced by
   rupToRes has an error.
   No files with tautologous clauses will be used for the verification
   track.