MAYBE
44.52/13.19	MAYBE
44.52/13.19	
44.52/13.19	Problem:
44.52/13.19	 a(a(x1)) -> x1
44.52/13.19	 a(b(x1)) -> x1
44.52/13.19	 b(b(a(x1))) -> a(b(a(b(b(x1)))))
44.52/13.19	
44.52/13.19	Proof:
44.52/13.19	 Open
44.52/13.19	EOF