Re: Mistake in the default serialisation of the RDF ontology

On 17/12/2021 14:02, Matthieu Bosquet wrote:
> The specific quote from "RDF Schema 1.1 - 5.3.3 rdf:predicate 
> <https://www.w3.org/TR/rdf-schema/#ch_predicate>" I am referring to 
> states the following:
> ---
> A triple of the form:
>
>     |S rdf:predicate P| 
>
> states that S is an instance of |rdf:Statement 
> <https://www.w3.org/TR/rdf-schema/#ch_statement>|, that P is an 
> instance of |rdf:Property 
> <https://www.w3.org/TR/rdf-schema/#ch_property>| and that the 
> predicate of S is P.
> ---
>
My bad, I missed that part.


> More specifically: "...P is an instance of |rdf:Property 
> <https://www.w3.org/TR/rdf-schema/#ch_property>|".
>
> My understanding is that this section describes which statements can 
> be inferred from one asserted statement of the form "S rdf:predicate 
> P"; one of which would be "P a rdf:Property"; which I believe means 
> that the range of rdf:predicate should be rdf:Property (which is not 
> only contrary to the default serialisation of the RDF ontology 
> <http://w3.org/1999/02/22-rdf-syntax-ns#>, but also to the following 
> sentence that you quoted).

Yes. As Richard also pointed out, the contradiction is in the RDFS 
Recommendation itself...

I'll add this in RDF's https://www.w3.org/2001/sw/wiki/RDF1.1_Errata, 
and credit you with it, if you don't mind.

>
> I also think that many foolish things can be said and it's a good 
> thing that, if anything, entailment helps realising how foolish the 
> things said are.

Agreed, but entailment should not "shoot the messenger", and treat as 
foolish any graph merely quoting a foolish statement.

Imagine I say "Alice believes that the earth is flat". You should not 
call me a flat earther for reporting this!

   pa

>> On 17 Dec 2021, at 10:29, Pierre-Antoine Champin 
>> <pierre-antoine@w3.org> wrote:
>>
>> 
>>
>>
>> On 17/12/2021 00:04, Matthieu Bosquet wrote:
>>> I'm reaching out because I think you might be able to help or point 
>>> me in the right direction to fix what I think is a mistake in the 
>>> default serialisation of the RDF ontology dereferenceable at 
>>> http://w3.org/1999/02/22-rdf-syntax-ns# <https://t.co/2fWsLy0dpC>.
>>>
>>> According to RDF Schema 1.1, I think the rdfs:range of rdf:predicate 
>>> should be rdf:Property as per 
>>> https://w3.org/TR/rdf-schema/#ch_predicate <https://t.co/hN2YnAwnhv>.
>>
>> The section you are pointing to states
>>
>> "rdf:predicate is an instance of |rdf:Property| 
>> <https://www.w3.org/TR/rdf-schema/#ch_property>"
>>
>> meaning rdf:predicate is /itself/ an instance of rdf:Property.
>> This sentence is not about the values of rdf:predicate...
>>
>> The same section states, a little below:
>>
>> "The |rdfs:domain| <https://www.w3.org/TR/rdf-schema/#ch_domain> of 
>> |rdf:predicate| is |rdf:Statement 
>> <https://www.w3.org/TR/rdf-schema/#ch_statement>| and the 
>> |rdfs:range| <https://www.w3.org/TR/rdf-schema/#ch_range> is 
>> |rdfs:Resource| <https://www.w3.org/TR/rdf-schema/#ch_resource>."
>>
>> which is consistent with the RDF description of the RDF vocabulary.
>>
>> Now, of course, I understand why one would expect the range of 
>> rdf:predicate to be rdf:Property. But I am not sure this would be a 
>> good idea. It would, for example, mean that
>>
>>     :someFool :said [
>>         a rdf:Statement ;
>>         rdf:subject rdfs:Class ;
>>         rdf:predicate rdfs:Class ;
>>         rdf:object rdfs:Class ;
>>     ].
>>
>> would RDFS-entail
>>
>>     rdfs:Class a rdf:Property.
>>
>> which does not seem desirable.
>>
>>   best
>>
>>>
>>> The current range is rdfs:Resource in the default serialization at 
>>> http://w3.org/1999/02/22-rdf-syntax-ns# <https://t.co/2fWsLy0dpC>.
>>>
>>> I know it's non-normative, but it seems like something that could be 
>>> nice to fix.
>>>
>>> Kind regards,
>>> Matthieu