MAYBE
0.08/0.17	MAYBE
0.08/0.17	
0.08/0.17	Problem:
0.08/0.17	 f(s(x),y,y) -> f(y,x,s(x))
0.08/0.17	
0.08/0.17	Proof:
0.08/0.17	 Open
0.08/0.18	EOF