MAYBE
214.74/56.01	MAYBE
214.74/56.01	
214.74/56.01	Problem:
214.74/56.01	 f(x,a(a(b(b(y))))) -> f(a(a(a(b(b(b(x)))))),y)
214.74/56.01	 f(a(x),y) -> f(x,a(y))
214.74/56.01	 f(b(x),y) -> f(x,b(y))
214.74/56.01	
214.74/56.01	Proof:
214.74/56.01	 Open
214.74/56.02	EOF