MAYBE
0.08/0.18	MAYBE
0.08/0.18	
0.08/0.18	Problem:
0.08/0.18	 -(x,0()) -> x
0.08/0.18	 -(s(x),s(y)) -> -(x,y)
0.08/0.18	 p(s(x)) -> x
0.08/0.18	 f(s(x),y) -> f(p(-(s(x),y)),p(-(y,s(x))))
0.08/0.18	 f(x,s(y)) -> f(p(-(x,s(y))),p(-(s(y),x)))
0.08/0.18	
0.08/0.18	Proof:
0.08/0.18	 Open
0.08/0.18	EOF