215.99/50.48	MAYBE
215.99/50.48	
215.99/50.48	Problem:
215.99/50.48	 b(b(b(b(x1)))) -> a(a(a(a(x1))))
215.99/50.48	 a(b(a(a(x1)))) -> b(b(b(b(x1))))
215.99/50.48	 b(a(b(a(x1)))) -> a(a(b(a(x1))))
215.99/50.48	
215.99/50.48	Proof:
215.99/50.48	 Open
215.99/50.49	EOF