1  
       2  extern void abort ();
       3  extern void exit (int);
       4  
       5  int f (int a) {
       6  	if (a != 2) {
       7  		a = -a;
       8  		if (a == 2)
       9  		  return 0;
      10  		return 1;
      11  	}
      12  	return 1;
      13  }
      14  
      15  int main (int argc, char *argv[]) {
      16  	if (f (-2))
      17  		abort ();
      18  	exit (0);
      19  }
      20