MAYBE
219.54/55.66	MAYBE
219.54/55.66	
219.54/55.66	Problem:
219.54/55.66	 a(l(x1)) -> l(a(x1))
219.54/55.66	 r(a(x1)) -> a(r(x1))
219.54/55.66	 b(l(x1)) -> b(a(r(x1)))
219.54/55.66	 r(b(x1)) -> l(b(x1))
219.54/55.66	
219.54/55.66	Proof:
219.54/55.66	 Open
219.54/55.66	EOF