MAYBE
140.26/55.41	MAYBE
140.26/55.41	
140.26/55.41	Problem:
140.26/55.41	 b(b(b(b(x1)))) -> b(b(b(a(b(x1)))))
140.26/55.41	 b(a(b(b(a(b(x1)))))) -> b(b(a(b(b(x1)))))
140.26/55.41	
140.26/55.41	Proof:
140.26/55.41	 Open
140.26/55.42	EOF