# 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>

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 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:47:49 UTC