[eclipse-clp-users] Delayed Goals

Hi,
   I will explain my doubt using an example. I have the following rule to
split a list. The first splitted list has the size N.

split(L,0,[],L).
split([X|Xs],N,[X|Ys],Zs) :- N $> 0, N1 $= N - 1, split(Xs,N1,Ys,Zs).

In Eclipse I can use it:

?- split([1, 2, 3, 4], 2, X1, X2).
X1 = [1, 2]
X2 = [3, 4, 5, 6]
Yes (0.00s cpu, solution 1, maybe more)

That is ok, but when I dont instantiate the size N, the Eclipse answers:

N = 0
X1 = []
X2 = [1, 2, 3, 4, 5, 6]
Yes (0.00s cpu, solution 1, maybe more)
N = 1
X1 = [1]
X2 = [2, 3, 4, 5, 6]
Yes (0.02s cpu, solution 2, maybe more)

... and goes on.

But I dont want this answer, I want eclipse to create delayed goals and wait
for new constraints. There is something I'm doing wrong?

Thank you in advance