How to use Spin ?
. Simulation
  $ spin [-p|-g|-l|-r|-s] promelafile
     -p shows state changes of processes every time step
     -g shows value of global variables every time step
     -l  shows local variables after process changes state
     -r  shows message receive events
     -s  shows message send events
. Verification
  $ spin –a [-m] promelafile (generate a C verifier pan.c)
  $ cc [-DBITSTATE] –o run pan.c (compile pan.c)
   ( -m modified sending behavior, cause it always executable)
    $ run ( generate pan.trail which can be inspected by spin with option –t)