Re: JESS: Truth Maintenance

I don't see where page 139 says anything about dependencies between  
facts. It does talk about how the state of the *agenda* is maintained  
-- the list of rules that haven't fired yet. But the effects of rules  
that fired in the past are not, by default, undone.

By default, there's no relationship between (aaa) and (bbb). Jess has  
the "logical" conditional element to specify dependencies among facts,  
and it can be used to easily implement your example below:

(defrule simpleRule
     (logical (aaa))
     =>
     (bbb))


It's discussed on pages 114-116 of Jess in Action.



On Jun 3, 2011, at 7:33 AM, Md Oliya wrote:

> Hi,
>
> I am doing some experiments with regards to truth maintenance.
>
> Assume that I have a rule like:
>
> (defrule simpleRule (aaa) =>(bbb))
>
> Asserting an (aaa) fact and (run)ning the rule will result in a new  
> fact (bbb).
> Nevertheless, retracting (aaa) will not retract (bbb) as well, and I  
> found it quite contrary to what was mentioned on page 139 of the  
> book "Jess in Action."
>
> Am I missing some config options?
>
> Thanks for your comments in advance.
> --Oli

---------------------------------------------------------
Ernest Friedman-Hill
Informatics & Decision Sciences          Phone: (925) 294-2154
Sandia National Labs
PO Box 969, MS 9012                            [email protected]
Livermore, CA 94550                             http://www.jessrules.com





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