#ifdef CHECK_FUNCTION_EXISTS

char CHECK_FUNCTION_EXISTS();
#ifdef __CLASSIC_C__
int main()
{
    int ac;
    char *av[];
#else
int main(int ac, char *av[])
{
#endif
    CHECK_FUNCTION_EXISTS();
    if (ac > 1000)
    {
        return *av[0];
    }
    return 0;
}

#else /* CHECK_FUNCTION_EXISTS */

#error "CHECK_FUNCTION_EXISTS has to specify the function"

#endif /* CHECK_FUNCTION_EXISTS */
