Follow the usage instructions on the Paragon website to download and
set up Paragon.

  http://www.cse.chalmers.se/research/group/paragon/

1) Create a directory for Paragon & for PrettyBook. Navigate to it.

   $ cd ~
   $ mkdir paragon
   $ cd paragon

2) Download Paragon, Paragon interface files, and Paragon runtime.

   $ wget http://www.cse.chalmers.se/research/group/paragon/downloads/distr/linux64/parac-0.2
   $ mv parac-0.2 parac
   $ chmod a+x parac
   $ wget http://www.cse.chalmers.se/research/group/paragon/downloads/lib/libPI.zip
   $ unzip libPI.zip
   $ wget http://www.cse.chalmers.se/research/group/paragon/downloads/lib/paragon_rt.jar

3) Get libffi (foreign function interface) to work w/ Paragon.
   Paragon uses an outdated version of this library. Fortunately,
   symlinking the old version to the new version works. This is a dirty 
   hack! You should delete this symlink (.6) once you're done w/ A5.
   
   $ sudo ln -s /usr/lib/x86_64-linux-gnu/libffi.so.7 /usr/lib/x86_64-linux-gnu/libffi.so.6
   
4) Download and extract PrettyBook into this directory.