Lisp HUG Maillist Archive

Multiple clauses in KW:FINDALL

Hi. I would like to query our kb using something similar to the following.
Assume I have to kw instances of class FRODO, one with age = 30, the other
with age = 60. I then evaluate:

(kw:findall '?x '(and (frodo ?x age ?age) ((< ?age 50))))

However, I clearly don't understand somthing about FINDALL, as the above
query returns *both* instances rather than just one. What am I doing wrong?

Thanks...

David E. Young
Bloodhound Software, Inc.
http://bloodhoundinc.com

"For wisdom is more precious than rubies,
and nothing you desire can compare with her."
  -- Prov. 8:11

"But all the world understands my language."
  -- Franz Joseph Haydn (1732-1809)


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Re: Multiple clauses in KW:FINDALL

Young, David wrote:

>Hi. I would like to query our kb using something similar to the following.
>Assume I have to kw instances of class FRODO, one with age = 30, the other
>with age = 60. I then evaluate:
>
>(kw:findall '?x '(and (frodo ?x age ?age) ((< ?age 50))))
>
>However, I clearly don't understand somthing about FINDALL, as the above
>query returns *both* instances rather than just one. What am I doing wrong?
>
>  
>
I think the (( ... )) syntax just means: run the Lisp code. The result 
is not used to control the Prolog backtracking. If you want the result 
to control the backtracking then I think you have to use (test ( ... )). ie
 

	(kw:findall '?x '(and (frodo ?x age ?age) (test (< ?age 50))))

__Jason
Updated at: 2020-12-10 08:55 UTC