streams

[Cliff Bender]

Hi, 

I'd like some help trying to understand the use of streams. As I
understand, this should produce a file 'out.txt', with the listing in
it. However, the listing gets printed to the screen, and the file is
empty:

| ?- open('out.txt', write, H, [alias(out)]), current_output(COUT), set_output(out), listing, set_output(COUT).

squint([], []).
squint([A|B], [C|D]) :-
        integer(A),
        C is A * A,
        squint(B, D).
squint([A|B], [A|C]) :-
        squint(B, C).

COUT = '$stream'(1)
H = '$stream'(2)

(1 ms) yes
| ?-

If anyone has any ideas, suggestions, anything, please reply.
Thanks and have a great weekend.
Cliff