MAYBE
220.21/55.73	MAYBE
220.21/55.73	
220.21/55.73	Problem:
220.21/55.73	 f(x,a(b(y))) -> f(a(b(b(x))),y)
220.21/55.73	 f(a(x),y) -> f(x,a(y))
220.21/55.73	 f(b(x),y) -> f(x,b(y))
220.21/55.73	
220.21/55.73	Proof:
220.21/55.73	 Open
220.21/55.73	EOF