Re: Two profiles: technical definition



> On 2 May 2024, at 16:55, Peter F. Patel-Schneider <pfpschneider@gmail.com> wrote:
> 
> That still doesn't make sense.  Bijective implies onto.   If all you want is one-to-one then that is injective or functional.

OK, you are right, it is a one-to-one function (namely injective), and not bijective. I confused one-to-ne with bijective. I have fixed that.

> Yes, any IRI can denote the integer 2, but having :Liz :spouse :Dick denote then integer 2 seems weird.

I don’t see why it is weirder than :Liz and <<(:Liz :spouse :Dick)>> denoting the same thing (which is possible), not necessarily the integer 2. 
RDF is plenty of spurious models like those; what matters is that they appear systematically for any graph, therefore they become irrelevant.

—e.

> 
> peter
> 
> 
> On 5/2/24 10:52, Franconi Enrico wrote:
>>> On 2 May 2024, at 16:39, Peter F. Patel-Schneider <pfpschneider@gmail.com> wrote:
>>> 
>>> Bijective means one-to-one and onto, so the transparent profile appears to be saying that every resource is a denotation of some triple term.  I think that the mapping should only be injective.  It might be better to state that RE is a function instead. The opaque profile has a similar problem.
>> You are right, I have to be more precise: RE is *bijective* covering only the whole IR x IP x IR (i.e., one-to-one and onto only over IR x IP x IR). Similarly for SRE.
>>> As well, this semantics allows for the SRE of a quoted triple to be something like the integer 2.  This probably has no bad consequences, but it is rather strange.
>> Also any IRI may have the same interpretation as the interpretation of the literal integer 2, since they are both resources. So, there is no difference here.
>> —e.
>>> peter
>>> 
>>> 
>>> On 5/2/24 03:05, Franconi Enrico wrote:
>>>> 
>>>> (I repeat a previous email, which could have been lost within a previous thread)
>>>> In order to make the upcoming discussion more concrete and technical, I have written down the formal definition of two profiles in the wiki:
>>>>  * RDF-star profile “transparent”
>>>>    <https://github.com/w3c/rdf-star-wg/wiki/RDF-star-profile-%22transparent%22> (namely many-to-many transparent)
>>>>  * RDF-star profile "functional opaque”
>>>>    <https://github.com/w3c/rdf-star-wg/wiki/RDF-star-profile-%22functional-opaque%22> (namely many-to-one opaque)
>>>> They rely on two distinct properties - rdf:reifies and rdf:edge (temporary name) - and on two distinct syntactic categories - tripleTerm and opaqueTripleTerm.
>>>> Technically, they could be just merged into a unique profile, which actually could be RDF-star itself.
>>>> —e.
>>>

Received on Thursday, 2 May 2024 15:18:42 UTC