- From: Olaf Hartig <olaf.hartig@liu.se>
- Date: Sat, 23 Jan 2021 18:34:03 +0100
- To: public-rdf-star@w3.org
Hi Thomas, On lördag 23 januari 2021 kl. 14:55:57 CET thomas lörtsch wrote: > [...] > >> But doesn’t this mean that in every case that you want to comment on a > >> triple with referential transparency you have to define a new property > >> with those specific semantics? > > > > I don't see why that would be necessary. Once I have introduced a property > > such as ex:statedBy (for which I have defined that > > referential-transparency > > inferences can be made for nested triples that have this property as their > > predicate), then I can use this property for any embedded triple. > > Of course you don’t have to define it anew in every case you want to use it > but you have to define a new property for all properties already defined, > or at least a good part of them. I don't think so. Notice, that properties such as my example ex:statedBy are meant to be used in the predicate position of *nested* triples. In contrast, most existing properties are not meant to be used for this purpose (of course, there are exceptions such as, e.g., properties in the Dublin Core vocabulary). > I find that a very high burden. See below > where I discuss several rdf*:isSubpropertyWithOpaqueSemantics (and > s/Opaque/Transparent/g) . > [...] > > From my reading of your initial example, you wanted the property > > ex:statedBy to have a meaning that allows for referential-transparency > > inferences. So, if you simply define it to have this meaning, then it is > > the property that was intended to be used, isn't it? > > [Just for keeping track of the flow of discussion: I didn’t introduce the > property ex:statedBy, you did] You are right! I realized this after sending the email and working on my response to James' email. > If one introduces an all new property for > every case where one desires to annotate a triple in a referentially > transparent way one would arrive at the problematic situation described > above, or even more problematic as now there is not even a relation between > the vocablaries we already have and the newly defined properties. > > My initial example can be looked up below, but here it is again, somewhat > shortened: somebody published the statement > :cars :are :bad . > > on the web. I want to annotate this statement by asserting > > << :cars :are :bad >> rdf:type :disputedClaim . > > In my original exampe I used the property :a to allude to rdf:type. Yes, I am aware that the "a" in your original example was the syntactic short form for rdf:type. I have explicitly discussed this example in the response to James that I have sent a few minutes ago. Best, Olaf > I made > that more explicit here. As the original statement refers to :cars under > the Non Unique Name Assumption of the semantic web I want my annotation to > do the same. How do I do that? Usage scenarios abound: people might have > defined mappings from ex:cars to WikiPedia, to the American Automotive > Makers Association's vocabulary etc and want to put those to use, people > might search for annotations on al subtypes of :vehicles etc pp. > > Another example could be that I want to state an n-ary relation like > > :me :travellingTo :Berlin . > > << :me :travellingTo :Berlin >> :on : Wednesday . > > There exist different IRIs for me and for Berlin and they are all valid. I > want the annotation to be valid with all those alternative IRIs, not just > with the ones I arbitrarily chose. > > It’s the semantic web and the NUNA is one of its founding principles. > Interoperability depends on it. RDF* as a syntax for Property raph style > n-ary relations depends on it too. If the above stated problem isn’t easy > to solve then that is a big problem for the proposed semantics. > > Thomas > > > Best, > > Olaf > > > >> That seems to need a > >> new property like > >> > >> rdf*:isSubpropertyWithOpaqueSemanticsOf > >> > >> or even > >> > >> rdf*:isSubpropertyWithOpaqueSemanticsInDomainOf > >> rdf*:isSubpropertyWithOpaqueSemanticsInRangeOf > >> rdf*:isSubpropertyWithOpaqueSemanticsInDomainAndRangeOf > >> > >> as different embedded triples in subject and object position might have > >> different semantics. So you’d get three subproperties per any property > >> from > >> any established vocabulary, right? Maybe not *all* of them but certainly > >> not a few in between. > >> > >> If this is indeed your proposal then I think you’ll have to come up with > >> something better. Or please explain what you meant instead. > >> > >> Thomas > >> > >>> Best, > >>> Olaf > >>> > >>> On torsdag 21 januari 2021 kl. 13:40:56 CET thomas lörtsch wrote: > >>>> [I hope I’m using the right terminology in the right way. Advice is > >>>> welcome.] > >>>> > >>>> The proposed semantics defines that the embedded triple refers to a > >>>> triple > >>>> on the syntactic level, not in the realm of interpretation. In defense > >>>> of > >>>> this rather peculiar arrangement Pierre-Antoine and Dörthe argued that > >>>> going from the syntactic to the interpreted triple is always possible > >>>> whereas the other way round it is not: once a triple is part of the > >>>> interpretation we can not know what its original syntactic structure > >>>> was. > >>>> That’s true (at least in any normal setup) but let's assume I’d like to > >>>> annotate not the syntactic triple but the interpreted triple. What > >>>> would > >>>> I > >>>> actually have to do to construct a reference to an interpreted triple > >>>> from > >>>> an RDF* embedded triple? > >>>> > >>>> > >>>> Lets for example assume someone published the triple > >>>> > >>>> :cars :are :bad . > >>>> > >>>> As he published that statement on the semantic web we can assume that > >>>> his > >>>> intend was to refer not only to :cars but just as well to :automobiles, > >>>> > >>>> :voitures etc. Now if we want to comment on that general interpretation > >>>> :of > >>>> > >>>> this statement, irrespective of the concrete vocabulary used, > >>>> irrespective > >>>> of any syntactic specifics, how would we do that? The proposed > >>>> semantics > >>>> of > >>>> > >>>> << :cars :are :bad >> :a :disputedClaim . > >>>> > >>>> doesn’t cover this very common case as the embedded triple only refers > >>>> to > >>>> that very specific syntactic form. From this RDF* statement we couldn’t > >>>> infer that > >>>> > >>>> << :automobiles :are :bad >> :a :disputedClaim . > >>>> > >>>> even if we were using a reasonably complete mapping of car related > >>>> vocabiularies. Adding all those derivable embedded triples to the > >>>> database > >>>> is not a viable option as it would increase operational costs > >>>> enormously. > >>>> We need a way to derive a reference to the interpreted triple from the > >>>> syntactic triple that the RDF* embedded triple represents. But how? > >>>> > >>>> > >>>> Thomas
Received on Saturday, 23 January 2021 17:34:23 UTC