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Re: [PRD] need Assign action

From: Michael Kifer <kifer@cs.sunysb.edu>
Date: Wed, 18 Jun 2008 16:10:12 -0400
To: "'RIF WG'" <public-rif-wg@w3.org>
Cc: Gary Hallmark <gary.hallmark@oracle.com>
Message-ID: <20080618161012.6a48cb20@kiferdesk>

Apropos: we talked about _new (a.k.a. Skolem) for BLD use cases, but never
decided anything. Should we try to put it in for the last call?


	--michael  


On Wed, 18 Jun 2008 09:52:28 -0700
Gary Hallmark <gary.hallmark@oracle.com> wrote:

> Adrian Paschke wrote:
> > It can not be simulated by a retract action followed by a new assert,
> > because if PRD has a negation (not) the retract might trigger a production
> > rule transition. But that is not the intended semantics of assign/update.
> >   
> what I meant was to add Assign to the definition of the transition 
> relation ?__RIF-PRD ? /P(W)/ × /L/ × /P(W)/ defined in Section 3.3 of 
> the PRD spec.  Assign would be defined as a single transition, not as 
> pair of (retract, assert) transitions.
> 
> Section 3.3 (and associated syntax section) needs some work in any 
> case.  There is no way to do what OBR calls "assert new", which means to 
> create a new frame with a brand new OID.  The existing PRD assert can 
> only take an existing frame and add a slot to it.
> Also, in OBR and in Jess, Retract would not take a frame argument, but 
> rather would take an OID and would retract all the frames that match 
> that OID.
Received on Wednesday, 18 June 2008 20:11:49 GMT

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