1  extern int foo (char*);
       2  extern void abort (void);
       3  
       4  extern char n[3];
       5  
       6  int main ()
       7  {
       8    int i, m = 0;
       9    for (i = 0; i < 3; i++)
      10      m += foo(&n[i]);
      11  
      12    if (m != 'b')
      13      abort ();
      14    return 0;
      15  }