0.00/0.50	MAYBE
0.00/0.50	
0.00/0.50	Problem:
0.00/0.50	add(x, 0()) -> x
0.00/0.50	add(x, s(y)) -> z <= add(s(x), y) = z
0.00/0.50	sub(z, y) -> x <= add(x, y) = z
0.00/0.51	
0.00/0.51	Proof:
0.00/0.51	ConCon could not decide confluence of the system.
0.00/0.51	
0.00/0.51	EOF