MAYBE
219.27/55.46	MAYBE
219.27/55.46	
219.27/55.46	Problem:
219.27/55.46	 a(b(b(x1))) -> b(a(a(x1)))
219.27/55.46	 a(a(b(x1))) -> b(b(a(x1)))
219.27/55.46	
219.27/55.46	Proof:
219.27/55.46	 Open
219.27/55.46	EOF