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

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/
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