Re: newbie: Out of local stack, matching values from 0 to 10

Hello Jan and Bart,
Thanks for the information.
I had never heard of tabling and XSB before, so I gave it a quick google. I can't say I understand it. I have little knowledge about resolution, but I understand tabling is another approach? I think I'll dig up my prolog books and read up on tabling, might be interesting..

For the time being, between(0, 9, X). Is good enough for me :)

Thanks again,
Matthijs.

Bart Demoen wrote: 
Jan Wielemaker wrote:

in_bounds(0).

in_bounds(X) :-
    in_bounds(Y),
    X is Y + 1,
    X < 10.
---


[..]


A Prolog system with tabling like XSB will (as far as I understand it)
fix this.  (but not for in_bounds(-1), right?)



No.
I assume you added
:- table in_bounds/1.
to the program.

Then also the query ?- in_bounds(-1). finishes in XSB, because:

    the goal with -1 does not unify with the first head
    the goal with -1 unifies with the second head, and in the
        body a new subgoal in_bounds(Y) is spawned and you were
        already convinced that when in_bounds is called with a
        free var, it finishes after some time, so this goal
        also consumes its answers - there are exactly 10 values
        for Y, but none of them is 1 less than the -1 (the X),
        so failure results

Right ?

Tabling is wonderfull, isn't it !

Cheers

Bart Demoen

.

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