197.55/50.53	MAYBE
197.55/50.54	
197.55/50.54	Problem:
197.55/50.54	 b(b(b(b(x1)))) -> b(b(b(a(b(x1)))))
197.55/50.54	 b(a(b(b(a(b(x1)))))) -> b(b(a(b(b(x1)))))
197.55/50.54	
197.55/50.54	Proof:
197.55/50.54	 Open
197.75/50.54	EOF