public boolean equals(Object obj) {
if (!obj.getClass().equals(this.getClass())) return false;
StateTreeString s = (StateTreeString) obj;
boolean ans =
(state.equals(s.state)
&& i.equals(s.i)
&& o.equals(s.o)
&& align[0] == s.align[0]
&& align[1] == s.align[1]
&& align[2] == s.align[2]
&& align[3] == s.align[3]);
return ans;
}
