MAYBE
252.71/64.31	MAYBE
252.71/64.31	
252.71/64.31	Problem:
252.71/64.31	 f(x,a(b(c(y)))) -> f(b(c(a(b(x)))),y)
252.71/64.31	 f(a(x),y) -> f(x,a(y))
252.71/64.31	 f(b(x),y) -> f(x,b(y))
252.71/64.31	 f(c(x),y) -> f(x,c(y))
252.71/64.31	
252.71/64.31	Proof:
252.71/64.31	 Open
252.71/64.31	EOF