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Re: [PRD] Issues to resolve before publication (ATOMIC as RULE)

From: Gary Hallmark <gary.hallmark@oracle.com>
Date: Mon, 30 Jun 2008 13:13:36 -0700
Message-ID: <48693E70.8020501@oracle.com>
To: Christian de Sainte Marie <csma@ilog.fr>
CC: RIF WG <public-rif-wg@w3.org>

consider this ruleset:

_P(0)
Forall ?x (_Q(?x) :- _P(?x))

I claim that this is a Core ruleset, valid in both PRD and BLD, and that 
in both dialects, _Q(0) is entailed.

Obviously, we want _P(0) to be a ground fact in both dialects.

Christian de Sainte Marie wrote:
> Gary Hallmark wrote:
>>>
>>> #7. Section 2.3.1 (Rule): Adrian added ATOMIC as a form of RULE, to 
>>> allow a RULE to be used to represent facts. However, a production 
>>> rule without a condition is not a fact: it is an unconditional 
>>> action. I
>>
>> what are you talking about?  PRD and BLD both need ground facts, and 
>> both should use the same syntax (ATOMIC) to express it.
>
> Yes. But the conclusion of a production rule is an action, not a fact, 
> even if it can be syntactically disguised to look like one.
>
> It may be the unconditional assertion of a fact, if it contains no 
> variable and the condition is omitted or tautologically true, but that 
> does not make it a fact.
>
> (In addition, PRD does not allow the assertion of arbitrary ATOMICs).
>
>>> propose to revert to the previous version, as in [1], where the "if"
>>> part can be omitted (meaning ture by default) , to represent rules 
>>> where
>>> the action part is intended to be executed for all the bindings of the
>>> varaibles.
>>
>> No. This is an unjustified deviation from BLD.
>
> So, yes, it seems to be a justified deviation from BLD.
>
> Christian
>
Received on Monday, 30 June 2008 20:16:19 GMT

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