1  extern int circlemod1 (void);
       2  extern int circlemod2 (void);
       3  
       4  int
       5  circlemod3 (void)
       6  {
       7    return 3;
       8  }
       9  
      10  int
      11  circlemod3a (void)
      12  {
      13    return circlemod1 () + circlemod2 ();
      14  }