scc

 1int but, aclick;
 2
 3int
 4main(void)
 5{
 6	int r;
 7
 8	r = 0;
 9	if (aclick == 1 && but)
10		r = but == 1 && aclick == 0;
11	if (aclick == 0 && but)
12		r = but == 1 || aclick == 0;
13	if (aclick == 1 && but == 0)
14		r = !but;
15	return r;
16}