MAYBE
157.72/55.32	MAYBE
157.72/55.32	
157.72/55.32	Problem:
157.72/55.32	 b(b(b(x1))) -> a(a(a(x1)))
157.72/55.32	 a(a(a(x1))) -> b(a(b(x1)))
157.72/55.32	
157.72/55.32	Proof:
157.72/55.32	 Open
157.72/55.32	EOF