980618-1.c

this is a gcc file, you can download it and learn its usetility, for further detail please look at t

void func(int, int);

int main()
{
        int x = 7;
        func(!x, !7);
	exit (0);
}

void func(int x, int y)
{
        if (x == y)
                return;
        else
                abort ();
}