#define   N 4

byte Fork[N];

#define Think( I )  printf( "Think %d\n", I )
#define Eat( I )    printf( "Eat %d\n", I )

proctype Philosopher( byte I ) {
   do
   :: Think( I ) ;
      atomic { (Fork[I] > 0);       Fork[I]-- } ;
      atomic { (Fork[(I+1)%N] > 0); Fork[(I+1)%N]-- } ;
progress:
      Eat( I ) ;
      Fork[I]++;
      Fork[(I+1)%N]++;
   od
}

init {
   byte   ind ;
   assert( N > 2 ) ;
   atomic {
      ind = 0;
      do
       :: (ind >= N) -> 
          break;
       :: else ->
          Fork[ind] = 1;
          ind++;
      od;
      ind = 0;
      do 
       :: (ind >= N) ->
          break;
       :: else ->
          run Philosopher( ind );
          ind++;
      od;
   }
}