1  extern void a(void);
       2  extern void b(void);
       3  
       4  void dummy (void)
       5  {
       6    a();
       7  }
       8  int
       9  compare (void (*f)(void))
      10  {
      11    return a == f;
      12  }
      13  int
      14  main (void)
      15  {
      16    b ();
      17    return 0;
      18  }