MAYBE
130.49/55.31	MAYBE
130.49/55.31	
130.49/55.31	Problem:
130.49/55.31	 b(b(b(x1))) -> a(a(x1))
130.49/55.31	 a(a(x1)) -> b(a(b(x1)))
130.49/55.31	
130.49/55.31	Proof:
130.49/55.31	 Open
130.49/55.31	EOF