W3C home > Mailing lists > Public > public-rif-wg@w3.org > March 2008

Re: [Fwd: Re: [DTB] Datatypes and Built-ins first run to clean up and extend the initial list]

From: Jos de Bruijn <debruijn@inf.unibz.it>
Date: Tue, 04 Mar 2008 16:46:07 +0100
Message-ID: <47CD6EBF.80907@inf.unibz.it>
To: axel@polleres.net
CC: Dave Reynolds <der@hplb.hpl.hp.com>, "Public-Rif-Wg (E-mail)" <public-rif-wg@w3.org>


Axel Polleres wrote:
> Jos de Bruijn wrote:
>>
>>
>> Dave Reynolds wrote:
>>>
>>> Jos de Bruijn wrote:
>>>
>>>> So, we really want to take into account all IRIs representing a 
>>>> particular domain element.  Since this is a set, we would need to 
>>>> use a built-in predicates.  For example:
>>>>
>>>> "Let I be an interpretation, let u be an element in the domain of I, 
>>>> and
>>>> let {i1, ..., in} be the set of IRIs that denote u, i.e. for each ij 
>>>> (1 <= j <= n) IC(ij)=u.  IR(iriToString)(u,"ij")=t for (1 <= j <= 
>>>> n); IR(iriToString)(u,s)=f for every element s not in {"i1", ..., 
>>>> "in"}."
>>>>
>>>> The rule set
>>>> iriToString("b"^^rif:iri,"b"^^xsd:string)
>>>>
>>>> is satisfied in every RIF interpretation.
>>>
>>> But in any semantic web context  one couldn't determine the truth or 
>>> falsity of:
>>>
>>>  iriToString("foo"^^rif:iri,"bar"^^xsd:string)
> 
> 
> 
>> right.  In some interpretations the formula might be true, whereas in 
>> other interpretations it would be false.  So, it would not be entailed 
>> by the empty rule set.
> 
> but it would be entailed if the remaining theory entails
> 
>  "foo"^^rif:iri = "bar"^^iri
> 
> right?

Yes.


Jos

> 
> 
>> Best, Jos
>>
>>>
>>> Dave
>>
> 
> 

-- 
                          debruijn@inf.unibz.it

Jos de Bruijn,        http://www.debruijn.net/
----------------------------------------------
One man that has a mind and knows it can
always beat ten men who haven't and don't.
   -- George Bernard Shaw


Received on Tuesday, 4 March 2008 15:46:23 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 2 June 2009 18:33:47 GMT