Lisp HUG Maillist Archive

KW: invoking findall from predicate

Greetings. In our expert system we have some forward-chaining rules that
invoke predicates, via the TEST CE, that in turn apply some backchaining
goals via the functions ANY and FINDALL. These rules are exhibiting
non-deterministic behavior over the same data set, and I've tracked down the
cause to these predicates. If I replace these predicates with actual
instances reprenting the conditions defined by the predicates, the system
behaves properly.

Is there a restriction in KW that prohibits the predicate approach I've
described here? Clearly, predicates that do not invoke the backchainer are
not an issue. I don't want to get into why we chose this approach, but
suffice it to say it seemed to fit our environment nicely.

Regards,

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: KW: invoking findall from predicate

Young, David wrote:

>Greetings. In our expert system we have some forward-chaining rules that
>invoke predicates, via the TEST CE, that in turn apply some backchaining
>goals via the functions ANY and FINDALL. These rules are exhibiting
>non-deterministic behavior over the same data set, and I've tracked down the
>cause to these predicates. If I replace these predicates with actual
>instances reprenting the conditions defined by the predicates, the system
>behaves properly.
>
>Is there a restriction in KW that prohibits the predicate approach I've
>described here? Clearly, predicates that do not invoke the backchainer are
>not an issue. I don't want to get into why we chose this approach, but
>suffice it to say it seemed to fit our environment nicely.
>
>  
>
Hi,

I don't know of any such restriction. If there is a bug in KW then you 
are probably going to have to boil down the code to a small reproducible 
example or mail some of the source to see if we can eyeball the bug in 
the application.

__Jason


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