MAYBE
46.54/17.83	MAYBE
46.54/17.83	
46.54/17.83	Problem:
46.54/17.83	 a(a(a(x1))) -> b(x1)
46.54/17.83	 b(b(x1)) -> a(a(x1))
46.54/17.83	 a(a(x1)) -> a(b(a(x1)))
46.54/17.83	
46.54/17.83	Proof:
46.54/17.83	 Open
46.54/17.85	EOF