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RE: ISSUE-66 (Semantics of actions): Operational semantics of actions as covered by PRD? [PRD ]

From: Paul Vincent <pvincent@tibco.com>
Date: Fri, 20 Jun 2008 09:33:09 -0700
Message-ID: <637B7E7B51291C48838F5AE1F2ACA1D714D131@NA-PA-VBE02.na.tibco.com>
To: "Rule Interchange Format Working Group WG" <public-rif-wg@w3.org>

This is an interesting one that also caused much discussion in PRR.

1. Some PR engines allow separate maintenance of the "data model" and
"working memory". So an action can update the value of "foo" but this
could be invisible to the rule engine. 
2. Other rule engines do not allow data model and working memory to be
differentiated. So any update to "foo" is asserted automatically into
the working memory.

So if PRD supports type 1, this will require type 2 engines to (for
example) model foo_wm as well as foo, and an assert into working memory
will require a "foo_wm is set to foo" operation, with rules expressed in
terms of foo_wm.

If PRD supports type 2, this will preclude rulesets that exploit (e.g.
simplistic runtime optimization reasons) the assert vs update features
of the engine.

Paul Vincent
TIBCO | Business Optimization | Business Rules & CEP
 

> -----Original Message-----
> From: public-rif-wg-request@w3.org
[mailto:public-rif-wg-request@w3.org]
> On Behalf Of Rule Interchange Format Working Group Issue Tracker
> Sent: 20 June 2008 17:08
> To: public-rif-wg@w3.org
> Subject: ISSUE-66 (Semantics of actions): Operational semantics of
actions
> as covered by PRD? [PRD ]
> 
> 
> 
> ISSUE-66 (Semantics of actions): Operational semantics of actions as
> covered by PRD? [PRD ]
> 
> http://www.w3.org/2005/rules/wg/track/issues/
> 
> Raised by: Christian de Sainte Marie
> On product: PRD
> 
> - What should is the intended semantics of the actions covered by PRD?
> - What when the intended action is the creation or the deletion of an
> individual (object): is that part of the semantics of Assert/Retract?
How?
> - If (when) PRD covers some kind of Modify action, how should the
intended
> semantics differ from Retract+Assert?
> - Any kind of Execute action is, by definition, opaque: how should its
> semantics be specified, esp. wrt possible side effects on the state of
> facts wrt which the semantics of a PR system is specified in PRD?
> - etc...
> 
> 
Received on Friday, 20 June 2008 16:33:54 GMT

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