Re: [Sem] Yet another formal semantics for RDF-star

Le 27/03/2023 à 19:44, Peter F. Patel-Schneider a écrit :
> Hmm, yes.  I now think that you are correct.   I was incorrectly 
> treating the T mapping like the blank node mapping.  But now I'm not 
> sure exactly what this semantics is.   I would like to see more examples.

If we stay within az-semantics alone, it's hard to illustrate much. Let 
us consider an extension with owl:sameAs.

az-sameas semantics extends as-semantics in the following way:

an /az-sameas interpretation/ is an az-intepretation that satisfies this 
additional constraint:
  - I(owl:sameAs) in 𝓟
  - IEXT(I(owl:sameAs)) = {(x,x) | x in Δ}

In this case, we have:

:superman owl:sameAs :clark .
:lex :thinks <<:superman :can :fly>> .

az-sameas entails:

:lex :thinks <<:clark :can :fly>> .

Then,

:lex :assumes <<:superman owl:sameAs :clark>> ;
      :knows <<:superman :can :fly>> .

does *not* az-sameas entail:

:lex :knows <<:clark :can :fly>> .

*nor*:

:lex :assumes <<:clark owl:sameAs :superman>> .

Consider:

<<:s :p :o>> owl:sameAs :s .

az-sameas entails:

<<<<:s :p :o>> :p :o>> owl:sameAs :s .

The RDF-star graph:

<<:s :p :o>> owl:sameAs <<:x :y :z>> .

does *not* az-sameas entail:

:s owl:sameAs :x .


etc.

--AZ


> 
> peter
> 
> 
> On 3/27/23 13:40, Franconi Enrico wrote:
>> semantic vs syntactic predication has nothing to do with the existence 
>> or not of subject, predicate, and object relationships. It has to do 
>> with the identity of the reified object representing the embedded triple.
>> Is that object “representing” just the syntactic version of the 
>> embedded triple, or it represents the “meaning” of the embedded triple?
>> —e.
>>
>>> On 27 Mar 2023, at 19:36, Peter F. Patel-Schneider 
>>> <pfpschneider@gmail.com> wrote:
>>>
>>> Actually it is unclear what semantic predication should look like.   
>>> This proposal is reification plus uniqueness.   Whether that is 
>>> semantic predication depends on what one thinks the requirements for 
>>> semantic predication are.  One could argue that semantic predication 
>>> requires that there are resources that are actually triples, not just 
>>> that there are resources that are connected to resources via subject, 
>>> predicate, and object relationships.  I think that it would be 
>>> possible to add this extra requirement to the semantics.
>>>
>>> peter
>>>
>>>
>>>> On 3/27/23 13:28, Peter F. Patel-Schneider wrote:
>>>> Are you sure?  My reading is that this is semantic predication 
>>>> without assertion.    Consider the RDF graph { (( s p o ) q n) }.
>>>> A model of this graph is
>>>> ( { t' s' o' n' }, { p', q', rs', rp', ro' }, JS, {}, JT, JEXT, rs', 
>>>> rp' ro' )
>>>> with JS mapping s to s', o to o', n to n', p to p', and o to o',
>>>> JT( (s p o) ) =  t',
>>>> JEXT(q') = { ( t', n' ) }
>>>> JEXT(p') = {}
>>>> JEXT(rs') = { ( t', s' ) }
>>>> JEXT(rp') = { ( t', p' ) }
>>>> JEXT(ro') = { ( t', o' ) }
>>>> Note that JS has to map to resources or properties as in the RDF 1.1 
>>>> semantics.
>>>> In this semantics there is no entailment from { (( s p o) q n } to { 
>>>> (s p o)}
>>>> but there is entailment from { ((s p "42"^^xsd:int) q n) } to
>>>> { ((s p "42"^^xsd:integer) q n) } if xsd:int and xsd:integer are 
>>>> recognized datatypes.
>>>> peter
>>>>> On 3/27/23 13:02, Franconi Enrico wrote:
>>>>> I looked at it carefully. This seems to characterise more or less 
>>>>> the model theory of what I call syntactic predication, which is 
>>>>> more or less the current definition of <<.,.,.>>.
>>>>> Some comments - tell me if I’m wrong.
>>>>> Some difference I note is that a syntactically embedded triple 
>>>>> would still entail the truth of the triple itself, which probably 
>>>>> is not intended, and that the reification “implements” the full 
>>>>> semantic predication (ie., it would be fully transparent).
>>>>> Moreover, there is still the open discussion about injectivity, and 
>>>>> the interoperation, if desired, with the TEP and/or with the full 
>>>>> semantic predication.
>>>>> cheers
>>>>> —e,
>>>>>
>>>>>
>>>>>> On 27 Mar 2023, at 18:08, Antoine Zimmermann 
>>>>>> <antoine.zimmermann@emse.fr> wrote:
>>>>>>
>>>>>> Le 27/03/2023 à 17:37, Peter F. Patel-Schneider a écrit :
>>>>>>> It would be useful to have some more explanation and some examples.
>>>>>>
>>>>>> Yes, it is brutally asserting the definitions and nothing else.
>>>>>>
>>>>>>>   From my quick read this appears to be very lose to to using RDF 
>>>>>>> reification plus uniqueness of triples.
>>>>>>
>>>>>> Yes. The one benefit that I see is that it does not require 
>>>>>> introducing a vocabulary that would "reserve" some URIs.
>>>>>>
>>>>>>> In the Satisfaction section it appears that either a nor J[a] is 
>>>>>>> defined for blank nodes.
>>>>>>
>>>>>> Damn, I sometimes used bold face T as if it meant the set of all 
>>>>>> terms, while it is in fact defined as the set of RDF-star triples.
>>>>>>
>>>>>> α should be defined on "B ⋃ T ∖ Gnd".
>>>>>> There is an unfortunate copy-paste error before the colon of the 
>>>>>> 1st paragraph in section "az-Satisfaction"("𝓘[α](t) = : T → Δ" 
>>>>>> should be "𝓘[α]: T → Δ" and the second item of the first bullet 
>>>>>> list of this section should have "B ⋃ T ∖ Gnd" instead of "T ⋃ Gnd".
>>>>>>
>>>>>> I'll correct that.
>>>>>>
>>>>>> --AZ
>>>>>>
>>>>>>
>>>>>>> peter
>>>>>>>> On 3/27/23 09:09, Antoine Zimmermann wrote:
>>>>>>>> This is mostly for the semantics task force.
>>>>>>>>
>>>>>>>> I wrote this:
>>>>>>>> https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.emse.fr%2F~zimmermann%2FW3C%2FRDF-star-semantics%2F&data=05%7C01%7Cfranconi%40inf.unibz.it%7C628c4c949576455d6c3308db2ee9db12%7C9251326703e3401a80d4c58ed6674e3b%7C0%7C0%7C638155354154223295%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=QsK42%2FvCalgfkj6JBMxNx5l%2Be3zqe9L3LB7yHxL7ek4%3D&reserved=0
>>>>>>>>
>>>>>>>> The idea is that embedded triples are interpreted as arbitrary 
>>>>>>>> resources and the resources denoted by the subject, predicate, 
>>>>>>>> and object of an embedded triple are connected (semantically) to 
>>>>>>>> the embedded-triple-resource via 3 properties that depend on the 
>>>>>>>> interpretation.
>>>>>>>>
>>>>>>>> Now, please comment and destroy this proposal :)
>>>>>>
>>>>>> -- 
>>>>>> Antoine Zimmermann
>>>>>> ISI - Institut Henri Fayol
>>>>>> École des Mines de Saint-Étienne
>>>>>> 158 cours Fauriel
>>>>>> 42023 Saint-Étienne Cedex 2
>>>>>> France
>>>>>> Tél:+33(0)4 77 42 66 03
>>>>>> https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.emse.fr%2F~zimmermann%2F&data=05%7C01%7Cfranconi%40inf.unibz.it%7C628c4c949576455d6c3308db2ee9db12%7C9251326703e3401a80d4c58ed6674e3b%7C0%7C0%7C638155354154379524%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=0ngGhIU9nvczkbewEokms0xMi5cYu0ry2%2BuAjO1nml4%3D&reserved=0
>>>>>>
>>>>>>
>>>
> 

-- 
Antoine Zimmermann
ISI - Institut Henri Fayol
École des Mines de Saint-Étienne
158 cours Fauriel
42023 Saint-Étienne Cedex 2
France
Tél:+33(0)4 77 42 66 03
https://www.emse.fr/~zimmermann/

Received on Tuesday, 28 March 2023 08:45:39 UTC