1  extern void abort ();
       2  extern void exit (int);
       3  
       4  int f (int a) {
       5  	if (a != 2) {
       6  		a = a > 0 ? a : -a;
       7  		if (a == 2)
       8  		  return 0;
       9  		return 1;
      10  	}
      11  	return 1;
      12  }
      13  
      14  int main (int argc, char *argv[]) {
      15  	if (f (-2))
      16  		abort ();
      17  	exit (0);
      18  }
      19