#if defined (SYMBOL_100)
    This file is intended to be include by sample1.txt.
    If you want to switch back to sample1.txt, try the buttons on
    the File List Bar.

    // In sample1.txt, SYMBOL_100 is defined to be 100.
    // Let's define SYMBOL_200 based on SYMBOL_100
    #define SYMBOL_200 2 * SYMBOL_100

    // Undefin SYMBOL_100 here.
    #undef SYMBOL_100
#endif

