[rules-users] "Not" Non-Existential Quantifier

[Fenderbosch, Eric]

How is your rule base configured, with identity or equality assert
behavior?

________________________________

From: rules-users-bounces at lists.jboss.org
[mailto:rules-users-bounces at lists.jboss.org] On Behalf Of
ringsah at comcast.net
Sent: Monday, August 04, 2008 9:59 AM
To: Rules Users List
Subject: Re: [rules-users] "Not" Non-Existential Quantifier


Edson,
 
I finally succeeded in coming up with a simple test case that shows the
problem. I have attached the necessary files, which include a test case,
three fact objects, and the drl.
 
One key to this test are the fact that the Applicant fact object has an
"equals" method that tests for equality of its attributes, rather than
identity. A second key is that the applicant object is updated after it
is inserted.
 
It appears that what is happening is that an activation is created for
the rule that uses "not" when the applicant is inserted. Then, when the
applicant is updated, a second activation is created for that rule. It
should be cancelling the previous activation, but doesn't find it
because the Applicant instance no longer "equals" the fact object that
caused the activation.
 
Thanks!
-Hans

	-------------- Original message -------------- 
	From: "Edson Tirelli" <tirelli at post.com> 
	

	   Hans, 
	
	   Your reasoning is correct. There should not be 2 instances of
ApplicantStatus in the working memory. 
	
	   Can you provide a test case showing the problem? we have test
cases here using "not" and logical assertions, and it works properly.
	
	   Thanks,
	       Edson
	
	
	2008/7/31 <ringsah at comcast.net>
	

		How is "

		not" supposed to work with insertLogical? Assume I have
two different rules whose conditions are mutually exclusive, like the
following: 

		rule

		"Rule One" 

		

		when 

		

		not NegativeResult() 

		

		then 

		

		insertLogical(new ApplicantStatus("Approved")); 

		end

		rule

		"Rule Two" 

		

		when 

		

		NegativeResult() 

		

		then 

		

		insertLogical(new ApplicantStatus("Denied")); 

		end

		Assume that the above two rules are the only way an 

		ApplicantStatus fact can be inserted into working
memory. I would expect, after all rules are run, that it would be
impossible for there to be one ApplicantStatus with "Approved" as its
reason, and another with "Denied" as its reason, in the working memory. 

		I would expect that, before any 

		NegativeResult is inserted, that rule one could run, and
insert an ApplicantStatus fact with an "Approved" reason. Then, after a
NegativeResult is inserted, that rule two could run, and insert an
ApplicantStatus fact with a "Denied" reason. At this point I would
expect that the original ApplicantStatus fact, with an "Approved"
reason, would be retracted, since the conditions under which it was
inserted are no lon! ger true. 

		This is not what I am observing, however. I am finding 

		ApplicantStatus facts with both reasons in working
memory at the end of the rules run. Should "not" work as I expect with
regard to inserting a fact via insertLogical()? Or is this a known
limitation, or simply the way it is designed to work? 

		Thanks,

		-Hans


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	-- 
	Edson Tirelli
	JBoss Drools Core Development
	JBoss, a division of Red Hat @ www.jboss.com
<http://www.jboss.com/> 
	

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