MAYBE
0.08/0.19	MAYBE
0.08/0.19	
0.08/0.19	Problem:
0.08/0.19	 le(0(),y) -> true()
0.08/0.19	 le(s(x),0()) -> false()
0.08/0.19	 le(s(x),s(y)) -> le(x,y)
0.08/0.19	 app(nil(),y) -> y
0.08/0.19	 app(add(n,x),y) -> add(n,app(x,y))
0.08/0.19	 low(n,nil()) -> nil()
0.08/0.19	 low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x))
0.08/0.19	 if_low(true(),n,add(m,x)) -> add(m,low(n,x))
0.08/0.19	 if_low(false(),n,add(m,x)) -> low(n,x)
0.08/0.19	 high(n,nil()) -> nil()
0.08/0.19	 high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x))
0.08/0.19	 if_high(true(),n,add(m,x)) -> high(n,x)
0.08/0.19	 if_high(false(),n,add(m,x)) -> add(m,high(n,x))
0.08/0.19	 head(add(n,x)) -> n
0.08/0.19	 tail(add(n,x)) -> x
0.08/0.19	 isempty(nil()) -> true()
0.08/0.19	 isempty(add(n,x)) -> false()
0.08/0.19	 quicksort(x) -> if_qs(isempty(x),low(head(x),tail(x)),head(x),high(head(x),tail(x)))
0.08/0.19	 if_qs(true(),x,n,y) -> nil()
0.08/0.19	 if_qs(false(),x,n,y) -> app(quicksort(x),add(n,quicksort(y)))
0.08/0.19	
0.08/0.19	Proof:
0.08/0.19	 Open
0.08/0.19	EOF