Re: soundness and semantics

Sandro Hawke wrote:
> (general agreement -- a few comments.)
>
>   
>> It seems to me that behind the "soundness" discussions, the "semantics"
>> issue is re-emerging.  My understandsing is as follows:
>>
>> 1. Interchange of rules and rule sets originally specified after
>> different semantics is needed. Therefore, the possibility of RIF rules
>> and rule sets with different semantics should be a requirement.
>>     
>
> I understand you to be saying RIF will need to have different dialects,
> each with its own semantics.  Are you thinking of 2-5 standard dialects
> or more than 6?
>   

The aboved does not refer directly or necessarily to several dialectrs.
It means exactly whgat ui worte, not less, not more. E.g. I couldd say,
rule set ( not a => b, not b => a } with FOL semantics or
 rule set ( not a => b, not b => a } with well-founded semantics. I see
no dialects there.
> And if more more than 6, so you see a way to keep this manageable?
>
>   
>> 2. Such an interchange is only possible if the original semantics of the
>> rules and rule sets to be interchanged is specified. Therefore, the
>> possibility to specify a semantics for a rule or rule set should be a
>> requirement.
>>     
>
> That only comes up if there were rulesets with the same syntax by
> different semantics, right?  
Not only. This is onlty one possibility -- but surely a possibility
worthwhile to consider.


> But that's only one approach: we could use
> different syntax (eg different namespaces or different element names)
> whereever we need different semantics.
>   

If the semantics is the same, I could be rather awkward to offer
different suyntaxes.

>> B1. fixpoint of an immediate consequence function (over rule sets and
>> facts).
>> B2. conflict resolution function (together with fixpoint of an immediate
>> consequence function).
>>     
>
> Some of us may not be familiar with these.  Can you point us to some web
> pages about them?   (maybe via the Wiki)
>   

I'll do my best, as soon as I have more time. I would have thopught
rthat both concepts were well-known. Maybe could some one else give
pointers? Hassan, could you please help?
>> 4. The notion of "sound" inferences from RIF rules and rule sets can,
>> and I think should, be defined as: inferences after the specified
>> semantics.
>>     
>
> I think that's what I've been saying.   *shrug*   Sorry if somehow it
> seemed different.
>   

Then, it is great! We were speaking the same language but did niot know!

:-)

Regards,

François

Received on Thursday, 11 May 2006 15:18:25 UTC