1  /* Included from 20000628-1.h.  This header is supposed to be seen
       2     exactly three times.  */
       3  
       4  #if !defined A
       5  #define A
       6  int a;
       7  #elif !defined B
       8  #define B
       9  int b;
      10  #elif !defined C
      11  #define C
      12  int c;
      13  #else
      14  #error Included a fourth time
      15  #endif