Re: Three ideas

Hi Fabio

First of all, I would like to apologize to you and to Anthony, if I gave
> the impression of trying to hijack your/his proposed topic into a
> discussion of the things only I care about. That was not my plan and is not
> my habit.
>

You're in no way at all hijacking anything. You're basically the only
person who openly showed some sort of support for what I've said from the
beginning, so for that you have permission to hijack any thread of mine for
life :-)

In all seriousness though, engineers can be very good at optimizing but we
often optimize the wrong thing, so in my view you're just making sure that
things are being talked about at the right level, which is the right thing
to do and it's definitely part of this discussion. I haven't replied
because I haven't come to any strong view on it yet, but to show that
I'm listening this is my very rough current view:

We're always trying to describe states of affairs/situations. Our basic
unit of description is the triple, so we're always describing
relationships/events. Sometimes, without IDs for everything, you need to
disambiguate these events by locating them in time and space. Even the
triple in your example about water:

:H2O :form :Liquid

It can be made "simply true", as Pat puts it, if it describes a state of
affairs and you locate that state of affairs in time and space, for example:

:H2O :form :Liquid T1 T2 :LakeComo

It doesn't need the other things to be true, the above statement can stand
on its own as a unit of description. I think that's what separates time and
space from other contextual information, why it's taking precedence in this
discussion, and maybe why timestamping is a common practice, but I'm not
sure yet.

If you're describing conditions that could lead to a state of affairs, then
maybe that's a different way of using RDF and I haven't given it enough
thought to say anything else about it yet, it would seem to be more like a
formula I guess.

But really, my thoughts are only half-formed on this, so feel free to
bounce more ideas around, here or another thread I don't mind.

Regards
Anthony


On Fri, Jan 21, 2022 at 9:20 AM thomas lörtsch <tl@rat.io> wrote:

>
>
> > Am 20.01.2022 um 16:02 schrieb Fabio Vitali <fabio.vitali@unibo.it>:
> >
> > Dear Thomas,
> >
> >>> Everybody is focussing on a specific point (facts may or may not be
> temporally constrained) loosing sight of the large picture.
> >>
> >> Well, first of all, people aren’t overly respectfull of the subject of
> a thread. The thread I started, on Multisets, very quickly became turned
> into a thread about modelling time and other things. Now you want to stear
> this thread, which is about modelling time quite explicitly (as Anthony
> thinks this is so important that it requieres extending triples to quins
> with start and end date (optionally)) into the direction that you are
> interested in most. Maybe we could have more focused discussions, in
> seperate threads, and respect (and discuss in the proper place) each others
> main concerns?
> >
> > First of all, I would like to apologize to you and to Anthony, if I gave
> the impression of trying to hijack your/his proposed topic into a
> discussion of the things only I care about. That was not my plan and is not
> my habit.
>
> No need to apologize, and I am now becoming guilty of the same crime I
> fear.
>
> > The reason I put that introductory sentence is to notice that, of the
> full proposal of Anthony
> >
> >> Subject Relation Object T1 T2 SpatialBound Confidence
> >
> >
> > the only part that created clamor was the temporal part T1 and T2, as if
> time had some peculiar characteristics that made A.'s proposal hard to
> digest because of them.
> >
> > This clamor is something that I do not understand and in my message I
> tried to propose the idea that temporal constraints are neither different
> nor harder to accept that other types of constraints, including spatial,
> confidence, provenance, physical contexts, etc. I may have been rude, but
> it was my way to contribute to the debate about Anthony's proposal, and not
> an attempt to steer the discussion away from it. Sorry if it was felt in
> any other way.
> >
> >>> :JoeBiden :role :President.         is true only in the situation
> "jurisdiction is the United States"
> >>> :H2O :form :liquid.                 is true only in the situation
> "temperature between 0C and 99C, and pressure 1ATM"
> >>> :Beatles :betterThan :RollingStones is true only in the situation
> "opinion held by Fabio Vitali"
> >>>
> >>> and of course our favorite:
> >>>
> >>> :Burton marriedTo :Taylor.          is true only in the situation
> "temporal interval between 1964 and 1974"
> >>>
> >>> These sentences are all very similar: they aren't absolutely true, and
> they aren't absolutely false either.
> >>
> >> Yes.
> >>
> >> I agree that most if not all assertions are in some way contextual,
> dependend on certain circumstances, conceptualizations, theories,
> propositional attitudes etc. There are many circumstances and theories that
> many people agree on - e.g. the periodic table and algebra, as Pat likes to
> mention - but even they are theories, not absolute. What is absoluet
> anyways - I am (am I?).
> >
> > Indeed. Indeed.
> >
> >>> I do not think there should be any discussion about this: they are not
> facts, and stating these as RDF triples is a modelling error and they
> should be fixed in any reasonable representation of a domain.
> >>>
> >>> Do we agree on this?
> >>
> >> No. Definitely not.
> >>
> >> As I said before, in other mails: there is no complete discription of
> any real world entity, ever. The distinction of what is intrinsic and what
> is extrinsic to a description, what is important detail or circumstancial
> context, is arbitrary, always. Contexts may be well defined - when you talk
> about arithmetics, arabic numbers can be supposed to be an agreed upon
> context - or they may not.
> >
> > My point is: expressing as absolutely true a statement that is not
> absolutely true is not incomplete, it is wrong. The issue is not to have a
> complete description of the world, but that some description are clearly
> inconvenient and leading to problems.
> >
> > :DonaldTrump :role :USPresident   is true within the temporal semantics
> AT LEAST ONCE. :JoeBiden :role :USPresident   is true within the temporal
> semantics NOW. No sentence of the form ?someone :role :USPresident   is
> true within the temporal semantics ALWAYS. Assuming that all these temporal
> semantics are providing an incomplete representation of truth is
> misleading: they provide a wrong representation and this needs to be fixed.
> >
> > For instance, the current Italian Chamber of Deputy has 630 seats. In
> the current legislature, 641 people have been elected to a seat in the
> Chamber of Deputy. Why the difference? Because over time some have died,
> some have been elected to other posts, some have quit. At any moment in
> time we had 630 deputies or fewer, but over time the people involved were
> slightly more. Without temporal constraints, I would not have an incomplete
> representation, I would have a wrong representation.
>
> Well, I tried to explain my view on this in the past already but I’ll try
> again. It all depends on your expectations. The :role property in your
> example is not necessarily tensed. I can’t remember any property in any
> Semantic Web vocabulary to be tensed. They don’t explicitly say "now". They
> say that the relation exists, period. In this view all of your examples
> above are not wrong (or false, as the logian would prefer to say), they are
> true. The relation of :role between :Trump and :USPresident undoubtly
> exists. It is a relation that we can talk about and to which we add further
> properties like e.g. a timespan. That’s a way of looking at things. This
> glass is always half full. Given my postulate that no description can and
> will ever be complete it is also a very healthy way to look at things I
> claim. It is also what one experiences on the web: you google for
> "president USA" and you sure will get a few different results. That is
> normal, and easy to grasp. Everybody understands this. If you ask Google
> "Who _is_ the president of the United States" (emphasis by me) you’ll
> probably get the right answer. In general every moderatly well educated
> person will know that good results require good questions. Nothing new here
> either. So really, definitely no need for the kind of unasserted assertions
> that RDF-star embedded triples are.
>
> I asked before and I think you never answered how you think people should
> query your proposal. It would IMO very often require a two fold query,
> asking for the asserted and the unasserted assertion. That’s just
> laborious, tiresome, for really no good reason.
>
> Your whole idea IMO is quite overengineered, fixing (well, patching
> rather) a problem that doesn’t exist if you look at things the right
> (intuitive, I claim) way. Really, the kind of problem you’re trying to
> solve IMO only exists for people that got lost in semantic rat holes ;-)
>
> >>> Ok.
> >>>
> >>> How can we fix them?
> >>
> >> We can’t. We have to accept that what we express is always limited.
> That is kind of an Open World Assumption turned inwards. We have to find a
> way to deal with it and we have to align our formalisms accordingly.
> Anything else is futile.
> >
> > I agree. My point is not that we have to fix some bad descriptions:
> people do what they want to do, I am not going around with clubs forcing
> people to update their RDF.
> >
> > My whole point is that IF someone wants to fix their incorrect dataset,
> there is a way that totally disrupts it, n-ary relations,  replacing every
> single triple with 4 or 5 totally different ones,
>
> Pat recently explained two different variations: one is what you describe
> and IIUC it’s also called a star-scheme. The other one is the real n-ary
> relation and also known as snowflake-scheme, in which relations can branch
> out, but they are still relations in the original sense.
>
> E.g. (please forgive my sloppyness with the pseudo turtle syntax!)
>
> A star like scheme:
>
> E1 type event
>    participant X
>    activity goingToTheMovies
>    theatre Y
>    showing "The Abyss"
>
>
> The same as a snowflake:
>
> X goingToTheMovies _:b
> _:b theatre Y
>     showing "The Abyss"
>
> The snowflake still resembles the original idea of a triple, even more so
> if you replace ’showing’ by rdf:value. That’s what Pat prefers IIUC and it
> is definitely more true to the graph paradigm than the star scheme, but not
> necessarily easier to query I guess - that IMO very much depends.
>
>
> [That’s all I wanted to show. Then I got carried away and added more
> examples, for no good reason. But here you go.]
>
> Then there’s how I would prefer things to be modeled:
>
> X goingToTheMovies "The Abyss" #1
> #1 theatre Y
>    in <> // the local graph
>
> Provide a (maybe optional) identifier to triples and annotate them via
> that identifier.
>
>
> That identifier maps directly to the same as RDF standard reification:
>
> X goingToTheMovies "The Abyss"
> #1 a Statememt
>    subject X
>    perdicate goingToTheMovies
>    object "The Abyss"
>    in <> // the local graph
>    theatre Y
>
>
>
> Then there’s the same as RDF-star:
>
> X goingToTheMovies "The Abyss"
> #1 occurrenceOf << X goingToTheMovies "The Abyss" >>
>    in <> // the local graph
>    theatre Y
>
>
> Then there’s you approach
>
> << X goingToTheMovies "The Abyss" >> theatre Y
>
> because you don’t care much about referential transparency (but trust me:
> you should!) and because you expect people to query for unasserted
> assertions too (and use precisely the right URIs because you don’t care
> about referential transparency). You’d also have to introduce some
> intermediate if you wanted to disambiguate multiple occurrences of X going
> to the movies.
>
>
> > and another that is more conservative, using rdf-star, in which every
> non-absolutely-true triple is quoted and the constraints (temporal spatial,
> what-have-you) are added as qualities of the quoted triple.
> >
> >> A later archeological finding that Taylor was indeed adopted and
> originally a Smith will not invalidate anything said about her marriage
> with Burton. It just adds another aspect. If someone interprets it
> otherwise (e.g. a computer) then he doesn’t understand the world as it is
> (e.g. has no common sense). And as anybody slighty familiar with the topic
> of AI knows it is incredibly hard to operationalize common sense. I think
> you are postulating pipe dreams as something that RDF-star (or RDF, for
> that matter) has to persue and could conceivably be expected to fulfill.
> >>
> >> Instead we should expect that our formalisms always have a contextual
> component, implicits, and that those implicits may at some point not be
> shared, maybe unexpectedly so. And that at that point it would be very
> useful to be able to make such implicits explicit - to disambiguate,
> discuss, maybe come to new shared beliefs. A good formalism makes the
> common case easy but allows to refine it when needed. And refining a
> statement is not invalidating the original - at least it can be defined to
> not be. That definition won’t always hold and sometimes that will lead to
> problems but all in all it won’t. There is a fear of paradoxes embedded in
> Pat’s argument that I find quite exaggerated.
> >
> > I agree that the are always implicits. I am ready to accept without
> discussion the statement 2+2=4 because I understand we are implicitly
> adopting Peano's axioms. I am ready to accept basic chemistry and physics
> statements because we are implicitly accepting that we are sufficiently far
> from the Big Bang and from speeds close to C.
> >
> > But more mundane statements do not have the same shared implicits as
> basic chemistry and physics and mathematics.
> >
> >> Skipping most of the rest becase I don’t quite like neither RDF-star as
> defined by this CG nor Fabio's proposal to make conditionalized statements
> the new, tedious normal. Except one remark...
> >
> > Why tedious? I am totally fine if you disagree with them, you loathe
> them, you plan to fight them with all your strength... but tedious? Boring?
> This is sad and disappointing. :-)
>
> Ah, something got lost in translation I assume: tedious not in the sense
> of boring but monontonous, tiring, laborious…
>
> >>> These triples are now all ABSOLUTELY TRUE and correct. Not the
> internal triples, of course: they are still neither simply true nor simply
> false, and we could not assert them truly in any form. No: the outer
> triples are simply true.
> >>
> >> Notwithstanding that I do not endorse this proposal: are you aware that
> << :JoeBiden :role :President >> doesn’t refer to the person known by the
> name Joe Biden, a concept named role and a concept of presidency, but
> instead to the person known by the name Joe Biden AND refered to by the URI
> :JoeBiden (NOT e.g. that same person but refered to by the URI :JBiden or
> :JosephBiden etc), and analogously to the concept of presidency AS refered
> to by the URI :President (NOT the URI :PRESIDENT, or even
> wikipedia:President, dbpedia:President, LOC:President etc etc). And so on.
> Is that what you want? Do you find that useful in the general case? I’m
> asking because you propose to employ this way of modelling _in general_ and
> I wonder if the referentially transparent semantics of RDF standard
> reification weren’t in general much more appropriate. IMO you would have to
> go the route of the still informal :occurrenceOf property to arrive at the
> entities whose relation you actually woud like to annotate, conditionalize,
> whatever. I have the feeling that many proponents of RDF-star take it for
> what they would like it to mean, not for what it really is.
> >
> > I never entered the discussion about referential transparency. I do not
> want to.  Personally, I do not see much of a point in referential opacity,
> and I would live much more happily with referential transparency. Yet, I
> know that, when using the same IRI inside and outside of quoted triples,
> they both refer to the same entity. This is enough for me: there is a way
> out (duh: use the same IRI!), and if I understand this correctly
> referential opacity only makes it more difficult to use owl:sameAs. Well, I
> can live without it.
>
> IMO it rather has the potential to break the semantic web if used as
> carelessly as you suggest (and, to your defense, as advertized). That may
> be slightly exaggerated but it’s definitely a bigger problem than just a
> few missed owl:sameAs statements of which we have to many anyways. For
> someone so invested in correct semantics as you I find this lack of
> interest in a very foundational issue rather bewildering.
>
> To give you a somewhat drastic example: if you use quoted/embedded triples
> as defined per the proposed semantics you SAY that your annotation only
> holds for those specific URIs. How should I know if you really mean it of
> if you were just too lazy to create the :occurrenceOf intermediary? So are
> you speaking about a :President but not about a wikipedia:President? Even
> if I don’t know the exact answer I have to assume that you know what you
> are doing - especially as you are so crazy scrupulous about the conditions
> under which your statement is true - and I have to say: I will discard your
> statement. I don’t know if I know what you mean. I’m talking about a
> president as defined by Wikipedia, DBpedia, the Library of Congress and
> whoever else has a reasonably common sense understanding of the concept of
> a president. You don’t seem to be among those as you insist to use that
> very special URI and no other to refer to what you might call a president.
> As you don’t explain why or how your understanding of a president is
> different then those other conceptualizations from well known sources I
> have to shield myself against the possibility that you are some sectarian
> zealot with a very special view on reality that I don’t subsrcibe to. This
> concern is still valid even if you use the Wikipedia:president concept. I’m
> still suspicious: why only that, why not the others. There may be something
> strange about your worldview that I don’t subscribe to. Maybe Wikipedia's
> definition differs in a subtle but important way from other definitions
> that I’m not aware of. It seems important enough for you to use embedded
> triples instead of a referentially transparent representation. In short: I
> don’t know what you are talking about. You have left the common grounds of
> the semantic web as we know it. So, off your triple goes. I hope that is
> drastic enough as an example.
>
>
> Best,
> Thomas
>
>
> > Ciao
> >
> > Fabio
> >
> >
> >
> >>
> >> Best,
> >> Thomas
> >>
> >>
> >>> You may wonder what does each outer predicate mean in this context:
> :jurisdiction, :minTemp, :accordingTo, :start, and in all cases (time is
> not special in any way). Well, they have a quoted triple as the subject
> (and not an abstract entity instance of one of thousands of new ontological
> classes), and each expresses a different "locales" where the inner triple
> is "locally true". Some of them are jurisdictional or geographical, some of
> them are physical contexts, some of them are personal opinions. And some
> are temporal intervals.
> >>>
> >>> Their relationship with absolute truth is not in play, because they do
> not describe facts about JoeBiden, water, Beatles or Richard Burton, but
> qualities of some quoted triple. At the same time, each new triple is
> simply true. Just the very old and plain idea of truth, only not applied to
> new entities, but to quoted triples.
> >>>
> >>> In addition, although shielded by the quotation, the original triple
> is still there in its original form, with the original predicate and the
> original subject, and the overall number of triples is kept to a minimum.
> >>>
> >>> Finally, under this point of view, there is nothing special in time:
> time is just another quality of the situation that makes some statements
> non-absolutely-true. I do not believe we should focus so aggressively on
> time alone.
> >>>
> >>> Ciao
> >>>
> >>> Fabio
> >>>
> >>> --
> >>>
> >>> P.S.: I can see a philosophical underpinning of this discussion, as it
> seems to me that we are re-living the  "problem of the Universals" that has
> been running in philosophy since Plato vs. Aristotles, and then in late
> Middle Age Thomas Aquinas and Duns Scotus vs. Roscellinus and William of
> Ockham: by creating these abstract Entities, the :Term, the :Marriage, the
> :PhysicalState, the :Opinion, etc. we are forcing our ontologies to accept
> Universals that subsume and represent relations between Particulars, which
> are our original entities (JoeBiden, Beatles, Burton, etc.).
> >>>
> >>> About the existence of these Universals, well, there have been more
> that 2000 years of extreme discussions, so I do not think that we are
> allowed to simply say: yes, Universals are good for representing relations
> between Particulars, and that is the only way to go. Before rdf-star (AND
> conjectures) that was the only way out. With rdf-star, nominalists such as
> myself are not forced to contemplate thousands of arbitrary and hardly
> general abstract entities, but can work with the original relations and the
> original triples and just shield them inside quotations to avoid
> misrepresentations and misunderstandings.
> >>>
> >>> // Universals are flatus vocis, and as Umberto Eco famously wrote:
> "stat rosa pristina nomine, nomina nuda tenemus" ("the original rose is in
> the name, we can hold only names": the original rose, the rose that comes
> before any individual rose we can see, the Universal of the rose, exists
> only in name, not in reality".
> >>>
> >>>
> >>>
> >>>> On 20 Jan 2022, at 00:29, Pete Rivett <pete.rivett@agnos.ai> wrote:
> >>>>
> >>>> I'd like to strongly challenge the following from Anthony:
> >>>> "In RDF-Star, people are creating events by annotating triples with
> start and end times,"
> >>>> Who are these people? All I've seen is a (poorly chosen IMO) example
> in the CG document. I don't know of, and find it hard to conceive of,
> anyone sensibly doing this in a real system since it's just a poor modeling
> choice that will struggle to meet most use cases where the event matters.
> >>>>
> >>>> Overall I agree with Pat.
> >>>> To add, what was implicit in his response, RDF does not even have,
> and you have not proposed, Anthony, the notion of existence in RDF when you
> write "Things can't be in a relationship if they don't exist yet". RDF has
> no way to express "X rdf:createdAt T1" or "X rdf:destroyedAt T2" or "X
> rdf:hasLifetime [a rdf:Period; start:T1; end:T2]. And good luck with
> defining what the real world semantics would be - when does a Person or my
> Car or a City or a Color or a Product start and stop "existing"?
> >>>>
> >>>> More generally, I think this is a dangerous path: I think RDF, and
> RDF-star, provide our basic logic primitives that are there to be built
> upon to build more sophisticated systems for specific needs. OWL is one
> example.
> >>>> There may well be useful further such sophisticated systems that add
> different notions of temporality but it would IMO be egregious to force one
> specific approach into the core primitive layer. Since that's as primitive
> as it gets and would not allow alternative approaches that may deal
> differently with temporality or eschew it completely.
> >>>> To draw a parallel, most enterprise data right now is managed in
> relational databases: people have done pretty well with SQL not having
> temporal primitives. And it has allowed a relatively small number of people
> to build temporal databases, using different approaches, using SQL as is.
> >>>> So please let's not try to overburden RDF-star itself with one
> specific approach.
> >>>>
> >>>> Regards
> >>>> Pete
> >>>>
> >>>>
> >>>> On Wed, 19 Jan 2022 at 02:59, Anthony Moretti <
> anthony.moretti@gmail.com> wrote:
> >>>> Hi Pat! Thanks for joining the discussion!
> >>>>
> >>>> I honestly don't mind if all of the ideas I've put forward are wrong,
> I'll drop them the second there's a convincing argument against them and be
> happy to have learnt things in the process, it just doesn't seem like the
> case yet. So, let's jump in!
> >>>>
> >>>> That the atomic number of sodium is 11 is simply true. It is not true
> "at a time". To ask when it is true, or to try to give its truth some kind
> of temporal scope or limit, is to commit a category error.
> >>>>
> >>>> This was the example we talked about in private, and I'll retype what
> I said for the benefit of anybody who might be reading. In short I said:
> "Was it true ten minutes ago? Yes. Is it true now? Yes. Therefore even that
> relationship has an extent in time."
> >>>>
> >>>> On the Bette Davis example, maybe you can clarify something for me.
> Do Tarskian truth conditions apply in RDF? Sincere question because I've
> assumed that recently, but I don't know for sure. '"P" is true if, and only
> if, P'. Doesn't that imply bounds for temporal validity?
> >>>>
> >>>> If I have this triple:
> >>>>
> >>>> :JoeBiden :presidentOf :UnitedStates
> >>>>
> >>>> Isn't that true only for a period of time? Are we meant to avoid
> saying things like that? What about:
> >>>>
> >>>> :JoeBiden :name "Joe Biden"
> >>>>
> >>>> He could change his name in the future. It's becoming a bit unclear
> to me what I'm allowed to say in RDF or when I'm allowed to say them. If
> I'm meant to timestamp my graph, isn't that the same thing as saying it has
> a temporal validity?
> >>>>
> >>>> And even in a tensed language, we *can* speak of the future. We can
> even speak of futures that we believe will not exist: this happens all the
> time in planning, for example, where a reasoner might decide to not do
> something because it forsees that if it does do it, bad things will happen.
> So the present cannot be a bound. So what is the bound?
> >>>>
> >>>> Yes, I agree we can speak about the future, I made that point earlier
> in the thread. We can describe future events in the same way that we can
> describe fictional things. But those statements won't be true in a Tarskian
> sense until those futures eventuate, hence the present being an upper bound.
> >>>>
> >>>> I wonder, do you realize that you are not just arguing with RDF here,
> but with close to 1.5 centuries of formal philosophy of logic? Ever since
> Prior first described tense as a modality, tensed modal logics have been a
> clear subfield, but AFAIK nobody has concluded that all of logic must be
> tensed (still less spatially situated), or that the notion of truth is
> itself inherently temporal in nature.
> >>>>
> >>>> I just did a quick google of these things and it looks like an
> ongoing debate between tensed and tenseless theories of time, and some
> people arguing that both are valid. If that's so, does it hurt to add
> optional time and space positions like I'm suggesting? It feels intuitive,
> and I see it as a solution to a lot of modeling problems.
> >>>>
> >>>> Regards
> >>>> Anthony
> >>>>
> >>>>
> >>>> On Wed, Jan 19, 2022 at 5:17 PM Patrick J. Hayes <phayes@ihmc.org>
> wrote:
> >>>>
> >>>>
> >>>>> On Jan 17, 2022, at 8:02 PM, Anthony Moretti <
> anthony.moretti@gmail.com> wrote:
> >>>>>
> >>>>> If anybody isn't following Pierre-Antoine and me, I'll try to give a
> summary of what I think the problem might be, and I'll follow it with an
> example. There's an example in my last email too, Obama's first term as
> president.
> >>>>>
> >>>>> In typical modeling, events have an ID and you can use that ID to
> find statements about the start and end time of the event. If you have
> reoccurring events, like the celebrity marriage example, there's no problem
> because each event is uniquely identified.
> >>>>>
> >>>>> In RDF-Star, people are creating events by annotating triples with
> start and end times, and often there are accompanying annotations. If
> there's a reoccurring event, or if the annotations are only about a
> specific part of an event, when you do the expansions you no longer know
> which event the accompanying annotations are about because there are no
> event IDs and the core triples being used as the subject of those
> annotations are identical.
> >>>>>
> >>>>> In my view the problem isn't with RDF-Star it's with RDF. I think
> the basic unit of description, the triple, is missing components. Every
> triple describes a relationship and every relationship has an extent in
> time.
> >>>>
> >>>> Wrong.
> >>>>
> >>>>> Things can't be in a relationship if they don't exist yet
> >>>>
> >>>> Wrong
> >>>>
> >>>>> , and the future is yet to happen, those two things mean that every
> relationship is implicitly lower-bounded by the existence of the things
> being described
> >>>>
> >>>> Wrong
> >>>>
> >>>>> , and implicitly upper-bounded by the present.
> >>>>
> >>>> No, that is all completely mistaken. Relations as such have nothing
> whatever to do with time – unless, of course, they are relations between
> times or other temporal things. And a fact represented by an assertion
> (such as an RDF triple) of a relation holding between things need not  be
> inherently temporal in any way. That the atomic number of sodium is 11 is
> simply true. It is not true "at a time". To ask when it is true, or to try
> to give its truth some kind of temporal scope or limit, is to commit a
> category error.
> >>>>
> >>>> This is, or should be, simply obvious for facts about mathematics or
> scientific physical data, but it also true of many of the everyday
> asssertions found in ordinary prose. Take for example this, from a
> Wikipedia biography: "<Bette Davis> had her critical breakthrough playing a
> vulgar waitress in Of Human Bondage (1934) although, contentiously, she was
> not among the three nominees for the Academy Award for Best Actress that
> year." That sentences contains several linked assertions which are (I
> presume) true. But they are not true at any particular time. That Bette
> Davis played the part of a vulgar waitress in the move 'Of Human Bondage'
> in 1934 is TRUE. It is not true-now or true-after-1934 or -after-(5 April
> 1908). It is a simple fact.
> >>>>
> >>>> Now, you might object that it wasn't true in, say, 1921 (because it
> hadn't happened yet) or 1847 (because Bette Davis didn't exist then), but
> all such claims commit the same mistake, of taking truth to be something
> with a tense. Supose (perhaps at a seance) someone in 1847 had spoken this
> sentence, perhaps in a trance, and it had been carefully recorded at the
> time and then a historian in 1953 had found this record, would people say,
> Wow, what an amazing prediction? Or would they say, So what, it wasn't true
> in 1847, so it wasn't a prediction at all? Your rule would require the
> latter.
> >>>>
> >>>> Even if one takes the view (which I think you do) that all truth
> claims are tensed, time-relative, and the apparent timelessness of
> mathematical or scientific facts merely hides an implicit universal
> quantification, so that one should understand "the atomic number of sodium
> is 11" to be shorthand for "at all times T, the atomic number of sodium is
> 11 at time T"; even then, that Bette Davis played the part of a vulgar
> waitress in the move 'Of Human Bondage' in 1934, was just as true in 1847
> as it is now. Of course, nobody knew it was true then, and certainly nobody
> had any kind of epistemic licence to assert it back then; but it was true.
> That sentence is not in any way indexical, so its truth does not depend on
> when it was asserted (unlke, say "Bette Davis will appear in a movie 89
> years from now"), so if it is true when asserted in 1934 or 2021, then it
> is equally true when asserted in 1847 or indeed any other date. Our
> ignorance of a fact does not make that fact any less true.
> >>>>
> >>>> And even in a tensed language, we *can* speak of the future. We can
> even speak of futures that we believe will not exist: this happens all the
> time in planning, for example, where a reasoner might decide to not do
> something because it forsees that if it does do it, bad things will happen.
> So the present cannot be a bound. So what is the bound?
> >>>>
> >>>>> Some relationships have narrower extents in time than those two
> bounds, and some relationships have multiple discontinuous extents in time,
> but there's no place in a triple to describe those. Why? A similar idea
> applies to space, some relationships are only true in specific regions of
> space.
> >>>>
> >>>> I wonder, do you realize that you are not just arguing with RDF here,
> but with close to 1.5 centuries of formal philosophy of logic? Ever since
> Prior first described tense as a modality, tensed modal logics have been a
> clear subfield, but AFAIK nobody has concluded that all of logic must be
> tensed (still less spatially situated), or that the notion of truth is
> itself inherently temporal in nature.
> >>>>
> >>>>>
> >>>>> I believe a fix for this
> >>>>
> >>>> As the proverb says, if it ain't broken, don't fix it.
> >>>>
> >>>> Pat
> >>>>
> >>>>> would be optional time and space positions that can be left blank if
> not required:
> >>>>>
> >>>>>  Subject Relation Object T1 T2 SpatialBound
> >>>>>
> >>>>> With that, event ambiguity is resolved without the need for event
> IDs.
> >>>>>
> >>>>> I'll go into it in another email, but the temporal range should
> ideally be inclusive-start and exclusive-end, so some of my earlier
> examples actually need correction around that.
> >>>>>
> >>>>> Here's a more complex example that involves both time and space and
> builds on an example I gave at the beginning of the thread:
> >>>>>
> >>>>> Using existing RDF-Star, and mimicking how others appear to be using
> it:
> >>>>>
> >>>>> :BigMac :price-USD 5.66
> >>>>>  {|
> >>>>>      :quantitySold 550000000
> >>>>>      :statedIn :Wikipedia
> >>>>>      :region :UnitedStates
> >>>>>      :startTime 2021
> >>>>>      :endTime 2022
> >>>>>  |}
> >>>>>
> >>>>> Which expands to:
> >>>>>
> >>>>> :BigMac :price-USD 5.66
> >>>>> << :BigMac :price-USD 5.66 >> :quantitySold 550000000
> >>>>> << :BigMac :price-USD 5.66 >> :statedIn :Wikipedia
> >>>>> << :BigMac :price-USD 5.66 >> :region :UnitedStates
> >>>>> << :BigMac :price-USD 5.66 >> :startTime 2021
> >>>>> << :BigMac :price-USD 5.66 >> :endTime 2022
> >>>>>
> >>>>> There's so much ambiguity in both of the above. If the original
> intention was to describe the quantity sold in that specific region during
> that specific time then I think the expansion breaks that, or at the very
> least leaves it open to be broken by further statements if the price ever
> happens to be the same in a different period of time or a different region.
> Also, if the original intention was to say that all of the information was
> stated in Wikipedia, then I think the expansion breaks that too.
> >>>>>
> >>>>> A better way might be to use optional time and space positions and a
> "complex statement", which handily also results in metadata being separated
> from additional data:
> >>>>>
> >>>>> :BigMac :price-USD 5.66 2021 2022 :UnitedStates
> >>>>>  { :quantitySold 550000000 }
> >>>>>  {| :statedIn :Wikipedia |}
> >>>>>
> >>>>> Which expands to:
> >>>>>
> >>>>> :BigMac :price-USD 5.66 2021 2022 :UnitedStates
> >>>>> { :BigMac :price-USD 5.66 2021 2022 :UnitedStates } :quantitySold
> 550000000
> >>>>> << :BigMac :price-USD 5.66 2021 2022 :UnitedStates >> :statedIn
> :Wikipedia
> >>>>> << { :BigMac :price-USD 5.66 2021 2022 :UnitedStates } :quantitySold
> 550000000 >> statedIn :Wikipedia
> >>>>>
> >>>>> Even though this is a complex example, I think the time/space
> ambiguity and metadata ambiguity are both gone now.
> >>>>>
> >>>>> In summary, I feel like time and space positions should exist in RDF
> and it would fix some of the problems in RDF-Star too.
> >>>>>
> >>>>> Regards
> >>>>> Anthony
> >>>>>
> >>>>>
> >>>>> On Sat, Jan 15, 2022 at 1:48 PM Anthony Moretti <
> anthony.moretti@gmail.com> wrote:
> >>>>> I see your point, and I believe that's a valid approach. But I am
> not sure everyone wants to commit to that kind of ontological detail. As I
> wrote in my previous mail: conflating past and future event into the same
> class works well for many practical use cases.
> >>>>>
> >>>>> I agree. And, as Pete described, if the classification is important
> to a reasoner it can be done by the reasoner anyway. My point was just to
> say that implicit temporal bounds still seem to exist even for that very
> difficult example, and, by doing that, I was trying to chop away at reasons
> for not having optional time and space positions.
> >>>>>
> >>>>> In fact, optional time and space positions might actually help when
> describing future events because they let you easily set expiry dates for
> the things you say. For example, if you were planning WebConf2022 and the
> dates for it were still changing you could release a statement that was
> valid for only a certain period of time:
> >>>>>
> >>>>> :WebConf2022 :startDate "2022-04-25"^^xsd:date 2022-01-15 2022-01-21
> >>>>>
> >>>>> And then if plans change the following week and the event gets
> pushed back a month, which is happening a lot right now for in-person
> events (I know WebConf2022 is online), you could release an updated
> statement that was valid for a new period of time:
> >>>>>
> >>>>> :WebConf2022 :startDate "2022-05-23"^^xsd:date 2022-01-22 2022-01-28
> >>>>>
> >>>>>> Aside from modeling simplicity, I think the other major argument
> for time and space positions is that order of assertion matters.
> >>>>> ??
> >>>>>
> >>>>> Not in RDF, it does not.
> >>>>>
> >>>>>
> >>>>> I don't want to say I'm certain of this, but I think for triples
> that are time/space dependent and then used as the subject or object of
> another statement (in plain RDF via the use of identifiers) it does seem to
> matter. The triple needs to be completed first for further statements to
> make sense, and I think RDF-Star exposes the problem. If that's not the
> case can someone please give me a counterexample?
> >>>>>
> >>>>> The "Thomas traveling to Paris" example is a modification of an
> example Thomas gave in a different thread, and I'm dropping it because, as
> Pete also notices, it has various issues. The following example (Obama's
> first term in office) is an example I'm creating myself, but I'm sure
> people are going to try and do stuff like this because it's already
> happening with the celebrity marriage example:
> >>>>>
> >>>>> :BarackObama :presidentOf :UnitedStates
> >>>>>  {|
> >>>>>      :statedIn :Wikipedia
> >>>>>      :startTime 2009
> >>>>>      :endTime 2013
> >>>>>  |}
> >>>>>
> >>>>> What was stated in Wikipedia? The incomplete triple or the one
> completed by the temporal constraints? I think what is meant is the
> following, with the temporal constraints stated first and as additional
> data rather than metadata:
> >>>>>
> >>>>> :BarackObama :presidentOf :UnitedStates
> >>>>>  {
> >>>>>      :startTime 2009
> >>>>>      :endTime 2013
> >>>>>  }
> >>>>>  {| :statedIn :Wikipedia |}
> >>>>>
> >>>>> Even if the above format were available, people would probably still
> try to do something like:
> >>>>>
> >>>>> :BarackObama :presidentOf :UnitedStates
> >>>>>  {
> >>>>>      :secretaryOfState :HillaryClinton
> >>>>>      :startTime 2009
> >>>>>      :endTime 2013
> >>>>>  }
> >>>>>  {| :statedIn :Wikipedia |}
> >>>>>
> >>>>> But if the temporal constraints aren't asserted first you have a
> similar issue upon expansion because HillaryClinton wasn't Secretary of
> State for his entire presidency, only for his first term.
> >>>>>
> >>>>> Having optional time and space positions makes the order of
> assertion clear and the time-dependent triple is completed first before
> further statements are made. Separating additional data from metadata does
> the same thing and clarifies what the metadata is about:
> >>>>>
> >>>>> :BarackObama :presidentOf :UnitedStates 2009 2013
> >>>>>  { :secretaryOfState :HillaryClinton }
> >>>>>  {| :statedIn :Wikipedia |}
> >>>>>
> >>>>> RDF(-star) has no such notion. Assuming that what you wrote above is
> supposed to be RDF-star (replacing curly brackets with double angle
> brackets), then the semantics of RDF-star (directly inherited from RDF)
> requires that all four statements are interpretable independently of each
> other, and are all considered true (assuming that you "trust"/"accept" the
> whole graph as true).
> >>>>>
> >>>>> So I guess what I'm saying is that some triples, time/space
> dependent ones, don't stand on their own and can't be considered true or
> false, and instead of telling people to avoid them, or telling people to
> avoid forms like the above whose expansion will include incomplete triples,
> let's embrace them and design a solution for them. Bonus points that it's a
> super simple way to model things so it's great for beginners, bonus points
> that it also handles reoccurring events, bonus points that it solves for
> our other dimension, space, at the same time.
> >>>>>
> >>>>> To answer this question, we need to precisely specify the meaning of
> each term of the used ontology. Since this is your example, I would expect
> you to know... :-)
> >>>>>
> >>>>> The original example is Thomas', but aside from that, if there's
> ambiguity due to the chosen tense for the relation, which ideally shouldn't
> be a factor, then a lot of that goes away when you have valid times and can
> then opt for, say, present tense all of the time and have everything still
> be clear. The point I was trying to make though was that the triples were
> examples of the above, incomplete triples that need time/space information
> to complete them.
> >>>>>
> >>>>> But more importantly, I reiterate my request to be explicit about
> what you mean when you write "statement". Each RDF triple makes a
> statement, that IS either true or false. However, a given set of RDF
> triples might give an description of something else (e.g. an
> anthony-statement) that might be deemed *incomplete* for some uses.
> >>>>>
> >>>>> Once we have a clear distinction between rdf-statement and
> anthony-statement, then we can discuss whether a given set of
> rdf-statements provides a complete and accurate description of a given
> anthony-statement.
> >>>>>
> >>>>>
> >>>>> I'm still not clear what you mean by this, but I'll try to
> understand. Of the four statement types I proposed the closest to an RDF
> triple is a "Simple statement", which ideally would just be an RDF triple
> with optional time and space positions and the ability to have any type of
> statement as subject or object. A given set of simple statements, which
> would be provided using a compound statement that also has optional time
> and space positions, could then provide a complete and accurate description
> of any of the other statement types. Is that an answer to your question?
> Sorry if I've still misunderstood.
> >>>>>
> >>>>> Regards
> >>>>> Anthony
> >>>>>
> >>>>> On Sat, Jan 15, 2022 at 2:26 AM Pete Rivett <pete.rivett@agnos.ai>
> wrote:
> >>>>> I'd still take a modeling approach rather than ad hoc use of
> rdf-star annotations (which, as I pointed out in my last email, we have no
> way of documenting a schema for).
> >>>>>
> >>>>> From a modeling point of view I'd argue:
> >>>>> a) for modeling WebConf2022 as a simple Event. You could
> additionally and dynamically add the class FutureEvent using the
> restriction :startTime > now(). And, indeed PastEvent where :endTime <
> now().
> >>>>> if needed you could have an additional property :status with values
> appropriate to your interest in its lifecycle such as :Conceived,
> :Resourced, :Committed, :Announced, :Started, :Completed,
> :ProceedingsPublished.
> >>>>>
> >>>>> b) if you're interested in multiple journeys why not actually model
> them:
> >>>>> _journey1 a :Journey ;
> >>>>> :traveler :Thomas ;
> >>>>> :destination :Paris ;
> >>>>> :timing [a :Period;
> >>>>>    :start T1 ;
> >>>>>    :end :T2
> >>>>> ]
> >>>>> (you probably want an :origin place too)
> >>>>>
> >>>>> Generally I'd caution against trying to use Fictional: it becomes
> very subjective. For example is Klingon
> https://en.wikipedia.org/wiki/Klingon_language a fictional language? It
> originated in a fictional TV series but it has real speakers, works of
> literature and a language institute. And an official ISO language code
> (@tlh). If Klingon is fictional then why is Esperanto not?
> >>>>>
> >>>>> Pete
> >>>>>
> >>>>> On Thu, 13 Jan 2022 at 18:40, Anthony Moretti <
> anthony.moretti@gmail.com> wrote:
> >>>>> Earlier Pierre-Antoine wrote:
> >>>>>
> >>>>> Ok, let's take another example:
> >>>>>
> >>>>> :theWebConf2022 a s:Event ;
> >>>>>  s:startDate "2022-04-25"^^xsd:date ;
> >>>>>  s:endDate "2022-04-29"^^xsd:date .
> >>>>>
> >>>>> would you consider that those triple will only be valid on
> 2022-04-25? Or would you argue that this event already exists, even though
> it has not occurred yet?
> >>>>>
> >>>>>
> >>>>> This is a great discussion because I don't think time has been given
> the attention it deserves. The following are my current thoughts, I'm happy
> to hear more opinions though.
> >>>>>
> >>>>> There's a saying "the future is fiction until it happens". We can
> definitely talk about fictional things, Fabio gives the example of Mickey
> Mouse but you can even include abstract things like numbers, they're mental
> concepts and I'd argue that the concepts exist from the moment they're
> imagined. We can talk about fictional things without problem as long as
> it's understood that they're fictional, this can be explicit by saying
> Mickey Mouse is a FictionalCharacter, or implicit when talking about
> abstract things like numbers. You could create a hierarchy for fictional
> things by duplicating schema-org and prefixing all of the class names with
> "Fictional":
> >>>>>
> >>>>> Thing
> >>>>>  Person
> >>>>>  Place
> >>>>>  Event
> >>>>>
> >>>>> FictionalThing
> >>>>>  FictionalPerson
> >>>>>  FictionalPlace
> >>>>>  FictionalEvent
> >>>>>
> >>>>> I'd argue that past events belong in the first hierarchy and future
> events belong in the second, like so:
> >>>>>
> >>>>> FictionalThing
> >>>>>  FictionalEvent
> >>>>>      FutureEvent
> >>>>>
> >>>>> Pat mentioned Tarskian truth conditions, and I think the WebConf2022
> example fails that, even though it's convenient to describe it like that
> because it matches how you'd describe past WebConfs. It might be more
> accurate to say:
> >>>>>
> >>>>> :WebConf2021 a :Event
> >>>>>  :startDate 2021-04-19
> >>>>>  :endDate 2021-04-23
> >>>>>
> >>>>> :WebConf2022 a :FutureEvent
> >>>>>  :scheduledStartDate 2022-04-25
> >>>>>  :scheduledEndDate 2022-04-29
> >>>>>
> >>>>> And only once the event has happened, and a reality has occurred
> that can be described, describe it in the first manner like WebConf2021.
> >>>>>
> >>>>> Like I said, I'm happy to hear more opinions on all of this though.
> >>>>>
> >>>>> So I am still not convinced that triples are the right level of
> granularity for systematically attaching contextual metadata. Following
> Pat, I prefer to keep rdf-statements dead-simple (1), and model more
> complex things (like anthony-statements) with a bunch of triples.
> >>>>>
> >>>>> Aside from modeling simplicity, I think the other major argument for
> time and space positions is that order of assertion matters. If people
> annotate with start and end times, which they're already doing, then
> expansions don't work correctly. Going with an earlier example:
> >>>>>
> >>>>> :Thomas :travelingTo :Paris
> >>>>>  {
> >>>>>      :by :Train,
> >>>>>      :startTime T1,
> >>>>>      :endTime T2,
> >>>>>  }
> >>>>>
> >>>>> Would expand to:
> >>>>>
> >>>>> :Thomas :travelingTo :Paris
> >>>>> { :Thomas :travelingTo :Paris } :by :Train
> >>>>> { :Thomas :travelingTo :Paris } :startTime T1
> >>>>> { :Thomas :travelingTo :Paris } :endTime T2
> >>>>>
> >>>>> The first statement is incomplete, neither true or false, and the
> second statement has an incomplete statement as subject. What do either of
> those statements mean? Maybe someone has a better idea, but the only way I
> currently see around it would be custom expansion rules to do with time and
> space, which seems ugly to me.
> >>>>>
> >>>>> With time and space positions it would start as:
> >>>>>
> >>>>> :Thomas :travelingTo :Paris T1 T2
> >>>>>  { :by :Train }
> >>>>>
> >>>>> Which expands to:
> >>>>>
> >>>>> :Thomas :travelingTo :Paris T1 T2
> >>>>> { :Thomas :travelingTo :Paris T1 T2 } :by :Train
> >>>>>
> >>>>> Regards
> >>>>> Anthony
> >>>>>
> >>>>> On Fri, Jan 14, 2022 at 12:19 PM Pete Rivett <pete.rivett@agnos.ai>
> wrote:
> >>>>> Fabio, I don't know if it was deliberate, but it seems to me that
> using different preciates to bound periods such as :start, :end, :after,
> :before (and more?) seems to defeat the point (and I think what Anthony was
> looking for) to allow predictable querying and reasoning.
> >>>>> I really think it's premature for rdf-star to embody anything like
> this. I think we should start with a best practice note as suggested (even
> that will I think be hard enough to reach consensus on), then after
> sufficient demonstrated success with applying it for real, we could
> consider standardizing a specific set of predicates in a separate schema.
> >>>>> Which also invites the question "what would a schema for rdf-star
> annotation properties look like, and how could you specify the
> (required/permitted) use of specific annotation properties with specific
> regular properties?".
> >>>>>
> >>>>> BTW nary relationships need not need be as complex as your examples.
> Simpler alternatives:
> >>>>> _:item1 a :temporaryLocation;
> >>>>>   :affects :MonaLisa;
> >>>>>   :location :Florence;
> >>>>>   :hasPeriod [
> >>>>>     :start  "1506"^^xsd:Year;
> >>>>>     :end  "1517"^^xsd:Year;
> >>>>>   ] .
> >>>>>
> >>>>> _item1 a :USPresidency [
> >>>>> :holder :RichardNixon;
> >>>>> :hasPeriod [
> >>>>>  :start "1969-01-20"^^xsd:dateTime ;
> >>>>>  :end "1974-08-09"^^xsd:dateTime.
> >>>>> ]
> >>>>>
> >>>>> Cheers,
> >>>>> Pete
> >>>>>
> >>>>> On Thu, 13 Jan 2022 at 09:48, Fabio Vitali <fabio.vitali@unibo.it>
> wrote:
> >>>>> Hi!
> >>>>>
> >>>>>> On 13 Jan 2022, at 17:04, Pierre-Antoine Champin <
> pierre-antoine.champin@ercim.eu> wrote:
> >>>>>>
> >>>>>> Hi Anthony,
> >>>>>>
> >>>>>> you wrote
> >>>>>>
> >>>>>>> that the temporal validity of any statement is implicitly
> lower-bounded by the existence of the things that it talks about,       so
> technically the birth-date example is only valid after the birth date of
> the person
> >>>>>>
> >>>>>> Ok, let's take another example:
> >>>>>>
> >>>>>> :theWebConf2022 a s:Event ;
> >>>>>>  s:startDate "2022-04-25"^^xsd:date ;
> >>>>>>  s:endDate "2022-04-29"^^xsd:date .
> >>>>>>
> >>>>>> would you consider that those triple will only be valid on
> 2022-04-25? Or would you argue that this event already exists, even though
> it has not occurred yet?
> >>>>>>
> >>>>>> Without starting to count angels on pinpoints (wondering if a
> yet-to-be-born person exists or not), let's be pragmatic: does it make your
> knowledge base inconsistent in any way to consider that such triples about
> future events are already valid? I don't think so.
> >>>>>
> >>>>> You are adding two more pairs of terms, "valid / non valid" and
> "exist / not exist", to an already complex issue. The pairs already in play
> are:
> >>>>>
> >>>>> 1) true / false (or not-true?)
> >>>>> 2) asserted / not-asserted.
> >>>>>
> >>>>> True / not true attain to the relationship between statements and
> reality (or at least some notion of reality endorsed by logicians and a few
> mathematicians). Asserted / not asserted attain to whether we know that the
> current dataset contains the statement or not.
> >>>>>
> >>>>> [ Valid / not valid attain to correctness in expressing statements
> (e.g., according to an ontology), and exist /not exist attain to physical
> or philosophical understanding of reality which makes my mind quiver (Does
> Mickey Mouse exist?). ]
> >>>>>
> >>>>> I understand that here is a traditional, albeit vague, connection in
> this community between asserted and true, which I respect and uphold. But
> whatever is the contrary of true, I do not think there should be a similar
> connection between non-asserted and false (or not true).
> >>>>>
> >>>>> Non-asserted triples can be absolutely true (<< :theWebConf
> dc:subject :webTechnologies >>), absolutely false (<< :theWebConf :frontFor
> :mossadRecruitment >> ), and conditionally true (<< :theWebConf :rating
> :FiveStars >> ), depending on a lot of factors (time, location, provenance,
> confidence, etc.), and since rdf-star allows us to represent triples
> without asserting them, we can use it to express facts about non-asserted
> triples without worrying about their actual truth:
> >>>>>
> >>>>> << :theWebConf dc:subject :webTechnologies >>   :accordingTo
> :wikipedia.
> >>>>> << :theWebConf :frontFor  :mossadRecruitment >> :accordingTo
> :someMadman.
> >>>>> << :theWebConf :rating    :FiveStars >>         :accordingTo
> :FabioVitali.
> >>>>>
> >>>>> These triples are all asserted (and true (and valid!)) regardless of
> the truth value of their quoted triples. This is exactly what makes
> rdf-star very interesting to me.
> >>>>>
> >>>>> Now, using :theWebConf as in your example is somewhat misleading:
> you are using an Event, which is an abstract concept of something whose
> main characteristic is being temporally and geographically constrained, and
> then you ask if there are other temporal constraints associated to it. No,
> no, probably not. But you put yourself in an easy situation.
> >>>>>
> >>>>> Let's try with entities which are not events: say, a physical
> object, a role, a relationship:
> >>>>>
> >>>>> << :monaLisa :location :Florence >>
> >>>>> << :USA :president :RichardNixon >>
> >>>>> << :MickeyMouse inLoveWith :MinnieMouse >>
> >>>>>
> >>>>> All these triples are NOT absolutely true, and at the same time they
> are NOT absolutely false, either.
> >>>>>
> >>>>> Using rdf-star, we can create absolutely-true statements out of
> these non-absolutely-true triples:
> >>>>>
> >>>>> << :monaLisa :location :Florence >> :after "1506"^^xsd:Year; :before
> "1517"^^xsd:Year .
> >>>>> << :USA :president :RichardNixon >> :start "1969"^^xsd:Year; :end
> "1974"^^xsd:Year .
> >>>>> << :MickeyMouse inLoveWith :MinnieMouse >> :accordingTo :WaltDisney
> .
> >>>>>
> >>>>> These are trivial rdf-star representations of (simple)
> anthony-statements (syntax aside). I fail to see a downside to this.
> >>>>>
> >>>>> The opposite, to adopt "dead-simple statements" seems much worse to
> me: adopting n-ary relationships and events and states and opinions seems
> SO MUCH MORE COMPLICATED:
> >>>>>
> >>>>> _:item1 a :temporaryLocation;
> >>>>>   :affects :monaLisa;
> >>>>>   :location :Florence;
> >>>>>   :start [
> >>>>>       a :uncertainDate ;
> >>>>>       :after "1506"^^xsd:Year;
> >>>>>   ] ;
> >>>>>   :end [
> >>>>>       a :uncertainDate ;
> >>>>>       :before "1517"^^xsd:Year;
> >>>>>   ] .
> >>>>>
> >>>>> _:item2 a :temporaryState;
> >>>>>   :role :presidency;
> >>>>>   :organization :USA;
> >>>>>   :holder :RichardNixon;
> >>>>>   :startingEvent [
> >>>>>      a :election;
> >>>>>      :date "1969-01-20"^^xsd:dateTime.
> >>>>>   ];
> >>>>>   :endingEvent [
> >>>>>      a :resignation;
> >>>>>      :date "1974-08-09"^^xsd:dateTime.
> >>>>>    ].
> >>>>>
> >>>>> _:item3 a :fictitiousCouple;
> >>>>>   :member :MickeyMouse;
> >>>>>   :member :MinnieMouse;
> >>>>>   :type :Love;
> >>>>>   :inventedBy :WaltDisney.
> >>>>>
> >>>>> You may feel safer with n-ary relationships, i.e. with the
> objectification of relationships into abstract entities, but another way to
> express this concept is as "reification of triples into blank nodes" which
> seems to me exactly what rdf-star is about.
> >>>>>
> >>>>> We have rdf-star. Let's use it.
> >>>>>
> >>>>> Ciao
> >>>>>
> >>>>> Fabio
> >>>>>
> >>>>>>
> >>>>>> So I am still not convinced that triples are the right level of
> granularity for systematically attaching contextual metadata. Following
> Pat, I prefer to keep rdf-statements dead-simple (1), and model more
> complex things (like anthony-statements) with a bunch of triples.
> >>>>>>
> >>>>>> pa
> >>>>>>
> >>>>>> (1) even if, arguably, RDF-star makes them a little more complex
> that they originally were.
> >>>>>>
> >>>>>> On 13/01/2022 03:51, Anthony Moretti wrote:
> >>>>>>> Earlier I wrote:
> >>>>>>> the temporal validity of any statement is implicitly lower-bounded
> by the existence of the things that it talks about
> >>>>>>>
> >>>>>>> I wouldn't mind some feedback on this, but I think the temporal
> validity of every statement has an implicit upper bound too:
> >>>>>>>
> >>>>>>> Implicit lower bound: Existence of the things being described.
> >>>>>>> Implicit upper bound: Stated time of assertion, otherwise the
> present.
> >>>>>>>
> >>>>>>> If that's correct, I can use it to demonstrate optional time and
> space positions:
> >>>>>>>
> >>>>>>> It's 2010, and Pierre-Antoine sends me a graph. He puts a
> timestamp on his graph by upper-bounding the temporal validity:
> >>>>>>>
> >>>>>>> {
> >>>>>>>  :BarackObama :presidentOf :UnitedStates 2009 _,
> >>>>>>>  :JoeBiden :vicePresidentOf :UnitedStates 2009 _,
> >>>>>>>  :HillaryClinton :secretaryOfStateOf :UnitedStates 2009 _,
> >>>>>>> }
> >>>>>>>  _ 2010
> >>>>>>>
> >>>>>>> It's now 2022, and I'm working on my own graph:
> >>>>>>>
> >>>>>>> {
> >>>>>>>  :JoeBiden :presidentOf :UnitedStates 2021 _,
> >>>>>>>  :KamalaHarris :vicePresidentOf :UnitedStates 2021 _,
> >>>>>>>  :AntonyBlinken :secretaryOfStateOf :UnitedStates 2021 _,
> >>>>>>> }
> >>>>>>>
> >>>>>>> I trust Pierre-Antoine and remember that he sent me a graph a long
> time ago. I do the laziest thing possible and import it unmodified as a
> compound statement. The information is incomplete but the OWA means
> everything is ok, and the graph is still valid:
> >>>>>>>
> >>>>>>> {
> >>>>>>>  {
> >>>>>>>      :BarackObama :presidentOf :UnitedStates 2009 _,
> >>>>>>>      :JoeBiden :vicePresidentOf :UnitedStates 2009 _,
> >>>>>>>      :HillaryClinton :secretaryOfStateOf :UnitedStates 2009 _,
> >>>>>>>  }
> >>>>>>>      _ 2010,
> >>>>>>>  :JoeBiden :presidentOf :UnitedStates 2021 _,
> >>>>>>>  :KamalaHarris :vicePresidentOf :UnitedStates 2021 _,
> >>>>>>>  :AntonyBlinken :secretaryOfStateOf :UnitedStates 2021 _,
> >>>>>>> }
> >>>>>>>
> >>>>>>> I do automated flattening of the graph. The information is
> incomplete, but the graph is still valid:
> >>>>>>>
> >>>>>>> {
> >>>>>>>  :BarackObama :presidentOf :UnitedStates 2009 2010,
> >>>>>>>  :JoeBiden :vicePresidentOf :UnitedStates 2009 2010,
> >>>>>>>  :HillaryClinton :secretaryOfStateOf :UnitedStates 2009 2010,
> >>>>>>>  :JoeBiden :presidentOf :UnitedStates 2021 _,
> >>>>>>>  :KamalaHarris :vicePresidentOf :UnitedStates 2021 _,
> >>>>>>>  :AntonyBlinken :secretaryOfStateOf :UnitedStates 2021 _,
> >>>>>>> }
> >>>>>>>
> >>>>>>> I finally get the motivation and I update Pierre Antoine's
> statements. The information is now up to date and the graph is still valid:
> >>>>>>>
> >>>>>>> {
> >>>>>>>  :BarackObama :presidentOf :UnitedStates 2009 2017,
> >>>>>>>  :JoeBiden :vicePresidentOf :UnitedStates 2009 2017,
> >>>>>>>  :HillaryClinton :secretaryOfStateOf :UnitedStates 2009 2013,
> >>>>>>>  :JoeBiden :presidentOf :UnitedStates 2021 _,
> >>>>>>>  :KamalaHarris :vicePresidentOf :UnitedStates 2021 _,
> >>>>>>>  :AntonyBlinken :secretaryOfStateOf :UnitedStates 2021 _,
> >>>>>>> }
> >>>>>>>
> >>>>>>> I decide to send it back to Pierre-Antoine, and I put a timestamp
> on my graph:
> >>>>>>>
> >>>>>>> {
> >>>>>>>  :BarackObama :presidentOf :UnitedStates 2009 2017,
> >>>>>>>  :JoeBiden :vicePresidentOf :UnitedStates 2009 2017,
> >>>>>>>  :HillaryClinton :secretaryOfStateOf :UnitedStates 2009 2013,
> >>>>>>>  :JoeBiden :presidentOf :UnitedStates 2021 _,
> >>>>>>>  :KamalaHarris :vicePresidentOf :UnitedStates 2021 _,
> >>>>>>>  :AntonyBlinken :secretaryOfStateOf :UnitedStates 2021 _,
> >>>>>>> }
> >>>>>>>  _ 2022
> >>>>>>>
> >>>>>>> And so it could continue. Spatial validity would be handled
> similarly.
> >>>>>>>
> >>>>>>> It's very easy to reason about temporal/spatial validity when the
> approach to statements is unified and optional time and space positions can
> be used everywhere.
> >>>>>>>
> >>>>>>> Regards
> >>>>>>> Anthony
> >>>>>>>
> >>>>>>> On Wed, Jan 12, 2022 at 12:48 PM Anthony Moretti <
> anthony.moretti@gmail.com> wrote:
> >>>>>>> Correction, I was a bit sloppy:
> >>>>>>>
> >>>>>>> In both cases I would leave the time and space positions blank
> anyway, so RDF-as-usual.
> >>>>>>>
> >>>>>>> In the second example the space position would be blank, but not
> the time positions. I was just trying to agree that yes the second example
> isn't place-dependent.
> >>>>>>>
> >>>>>>> Regards
> >>>>>>> Anthony
> >>>>>>>
> >>>>>>> On Wed, Jan 12, 2022 at 12:44 PM Anthony Moretti <
> anthony.moretti@gmail.com> wrote:
> >>>>>>> Hi Pierre-Antoine
> >>>>>>> What is not entirely clear to me is how you see the ideas below
> interact with RDF-star —or RDF, for that matter...
> >>>>>>>
> >>>>>>> 1) Do you want to modify the core of RDF / RDF-star, replacing
> their notion of statement by the one you propose here (time+place
> annotated, complex and/or compound)?
> >>>>>>>
> >>>>>>> 2) Or do you want to explore how your proposed notion of statement
> could be expressed *on top* of RDF / RDF-star, with no or minimal
> modification to them?
> >>>>>>>
> >>>>>>> If the answer is 2 (my favorite option, by the way), then the idea
> is to model anthony-statements using a set of rdf-statements (possibly
> extended with RDF-star).
> >>>>>>>
> >>>>>>>
> >>>>>>> Ideally:
> >>>>>>> RDF: Time and space positions.
> >>>>>>> RDF-Star: Simple, compound, and complex statements.
> >>>>>>>
> >>>>>>> It would be ideal to put the time and space positions at the RDF
> level because, as Pat and Fabio seem to agree, some triples are time/space
> dependent and make no sense without that information. They're not edge
> cases either, it might seem like that because so far there hasn't been a
> way to express them, but there are infinitely many just as there are
> infinitely many that aren't time/space constrained. Also, the order of
> assertion is important for time/space dependent triples, if anything is to
> be said about them, additional data or metadata, then the time/space
> constraints need to be asserted first, and time and space positions ensure
> that order of assertion.
> >>>>>>>
> >>>>>>> I think it would help the discussion a lot to a) acknowledge that
> the word "statement" in this discussion is ambiguous, and b) to be as
> explicit as possible about which kind we are talking about.
> >>>>>>>
> >>>>>>> I'm using the word "statement" as a direct replacement for
> "sentence", so maybe "sentence" is a better term:
> >>>>>>>
> >>>>>>> sentence:
> >>>>>>> a set of words that is complete in itself, typically containing a
> subject and predicate, conveying a statement, question, exclamation, or
> command, and consisting of a main clause and sometimes one or more
> subordinate clauses.
> >>>>>>>
> >>>>>>> I am uncomfortable with "hard-coding" these 4 dimensions, and only
> them, in every possible statement. I think that the relevant dimensions
> depend on the relation itself (e.g., the birth-date of a person is neither
> time nor place dependent; the president of a country is not place
> dependent...). And I don't think that any list of contextual dimension can
> be exhaustive.
> >>>>>>>
> >>>>>>> Especially regarding certainty, there are many ways to model
> uncertainty (not all of them modelling it with a single value between 0 and
> 1, by the way).
> >>>>>>>
> >>>>>>>
> >>>>>>> On the first example you gave, my thoughts are that the temporal
> validity of any statement is implicitly lower-bounded by the existence of
> the things that it talks about, so technically the birth-date example is
> only valid after the birth date of the person, the birth date happens to be
> the object of the statement in this case but the idea would apply to any
> statement. On the second example, yes I agree its spatial validity is
> unbound. In both cases I would leave the time and space positions blank
> anyway, so RDF-as-usual.
> >>>>>>>
> >>>>>>> I'm happy to drop "certainty" for the reasons you stated. I've
> included it so far because it's another example of where order of assertion
> becomes important, for it to make sense it needs to be asserted after time
> and space but before metadata. But yes, let's drop it for now.
> >>>>>>>
> >>>>>>> And yes for sure, no list of contextual dimensions can be
> exhaustive, but if time and space positions are allowed it ensures those
> assertions are made first and the whole framework becomes scalable and
> easier to reason about.
> >>>>>>>
> >>>>>>> Do you have any clear definition, or at least guidelines, to
> decide whether a piece of information is additional data or metadata?
> >>>>>>>
> >>>>>>> My quick take would be: additional data continues the description,
> whereas metadata is description of the description.
> >>>>>>>
> >>>>>>> No widespread need, but logically it could continue, descriptions
> of descriptions of descriptions and so on:
> >>>>>>>
> >>>>>>> Simple statement
> >>>>>>>  { Additional data }
> >>>>>>>  {| First-order metadata |}
> >>>>>>>  {| Second-order metadata |}
> >>>>>>>  ...
> >>>>>>>
> >>>>>>> Fabio has a good idea with the note containing examples of good
> modeling.
> >>>>>>>
> >>>>>>> Regards
> >>>>>>> Anthony
> >>>>>>>
> >>>>>>> On Wed, Jan 12, 2022 at 8:02 AM Fabio Vitali <
> fabio.vitali@unibo.it> wrote:
> >>>>>>> Dear Pierre-Antoine,
> >>>>>>>
> >>>>>>>> 1) Do you want to modify the core of RDF / RDF-star, replacing
> their notion of statement by the one you propose here (time+place
> annotated, complex and/or compound)?
> >>>>>>>
> >>>>>>>
> >>>>>>> I think with you that RDFstar already provides a lot of what has
> been discussed so far.
> >>>>>>>
> >>>>>>> Yet Anthony explicitly mentions (and I agree with him) that
> RDFstar has the right approach for single triples, but is lacking in
> supporting the needs for complex and compound statements. Working towards
> some suggestions to integrate these needs would enrich and complete the
> RDFstar proposal.
> >>>>>>>
> >>>>>>> My preference would go towards exploiting named graphs, explicitly
> introducing unasserted named graphs that can then be used in RDFstar in the
> same way of unasserted triples.
> >>>>>>>
> >>>>>>>> 2) Or do you want to explore how your proposed notion of
> statement could be expressed *on top* of RDF / RDF-star, with no or minimal
> modification to them?
> >>>>>>>
> >>>>>>> I do not know Anthony's point of view on this, but I believe that
> it would be useful to think of a resource providing some thoughtful and
> general guidelines on how RDFstar's quoted and annotated triples (as well
> as, hopefully, the RDFstar's quoted and annotated named graphs that I
> envision) could help in expressing conditional, time-dependent,
> location-dependent, uncertain, opinionated and competing statements.
> >>>>>>>
> >>>>>>> What I am thinking is something like, say, a W3C note, on the
> lines of https://www.w3.org/TR/swbp-n-aryRelations/ : a document
> introducing no new features, but explaining and making examples on how to
> use the existing features in a possibly unexpected and innovative way.
> >>>>>>>
> >>>>>>> What do you think?
> >>>>>>>
> >>>>>>> Fabio
> >>>>>>>
> >>>>>>> --
> >>>>>>>
> >>>>>>>> On 11 Jan 2022, at 15:43, Pierre-Antoine Champin <
> pierre-antoine.champin@ercim.eu> wrote:
> >>>>>>>>
> >>>>>>>> Hi Anthony,
> >>>>>>>>
> >>>>>>>> thanks for the summary. It's hard to catch up for those of us who
> went offline during the break :-)
> >>>>>>>>
> >>>>>>>> On 08/01/2022 10:40, Anthony Moretti wrote:
> >>>>>>>>> Hi
> >>>>>>>>>
> >>>>>>>>> I thought I'd put the ideas I shared during the longer
> discussion in one place to make it easier for people to read and give
> feedback. I love what's been achieved so far, I just want whatever is
> released to be the best possible thing that could be released.
> >>>>>>>> What is not entirely clear to me is how you see the ideas below
> interact with RDF-star —or RDF, for that matter...
> >>>>>>>>
> >>>>>>>> 1) Do you want to modify the core of RDF / RDF-star, replacing
> their notion of statement by the one you propose here (time+place
> annotated, complex and/or compound)?
> >>>>>>>>
> >>>>>>>> 2) Or do you want to explore how your proposed notion of
> statement could be expressed *on top* of RDF / RDF-star, with no or minimal
> modification to them?
> >>>>>>>>
> >>>>>>>> If the answer is 2 (my favorite option, by the way), then the
> idea is to model anthony-statements using a set of rdf-statements (possibly
> extended with RDF-star). I think it would help the discussion a lot to a)
> acknowledge that the word "statement" in this discussion is ambiguous, and
> b) to be as explicit as possible about which kind we are talking about.
> >>>>>>>>
> >>>>>>>> I also have a few comments on the two first ideas:
> >>>>>>>>
> >>>>>>>>> (...)
> >>>>>>>>>
> >>>>>>>>> Summary:
> >>>>>>>>> 1. Optional time, space, and certainty positions.
> >>>>>>>> I am uncomfortable with "hard-coding" these 4 dimensions, and
> only them, in every possible statement. I think that the relevant
> dimensions depend on the relation itself (e.g., the birth-date of a person
> is neither time nor place dependent; the president of a country is not
> place dependent...). And I don't think that any list of contextual
> dimension can be exhaustive.
> >>>>>>>>
> >>>>>>>> Especially regarding certainty, there are many ways to model
> uncertainty (not all of them modelling it with a single value between 0 and
> 1, by the way). On that particular topic, you might be interested in this
> paper:
> https://hal.inria.fr/hal-02167174/file/Publishing_Uncertainty_on_the_Semantic_Web__Bursting_the_LOD_bubbles__Final_Version_.pdf
> >>>>>>>>
> >>>>>>>>> 2. Separating additional data from metadata.
> >>>>>>>> Do you have any clear definition, or at least guidelines, to
> decide whether a piece of information is additional data or metadata?
> >>>>>>>>
> >>>>>>>> best
> >>>>>>>>
> >>>>>>>>> 3. Simple, compound, and complex statements.
> >>>>>>>>> - - -
> >>>>>>>>>
> >>>>>>>>> 1. Optional time, space, and certainty positions
> >>>>>>>>>
> >>>>>>>>> We exist in time and space, and this type of modeling could
> possibly be easier. A statement would have four optional positions, leaving
> the time and space positions blank would mean "unbounded", and leaving the
> last position blank would mean 1.0:
> >>>>>>>>>
> >>>>>>>>> Subject Relation Object T1 T2 SpatialBound Certainty
> >>>>>>>>>
> >>>>>>>>> Examples:
> >>>>>>>>>
> >>>>>>>>> :RichardB :marriedTo :LizT 1964 1974
> >>>>>>>>> :RichardB :marriedTo :LizT 1975 1976
> >>>>>>>>>
> >>>>>>>>> :BigMac :price-USD 7.30 T1 T2 :Switzerland
> >>>>>>>>> :BigMac :price-USD 1.62 T1 T2 :India
> >>>>>>>>>
> >>>>>>>>> If anybody has worked with temporal databases they might see an
> analogy with "valid times". By extension, the spatial bound could be
> thought of as a "valid place".
> >>>>>>>>>
> >>>>>>>>> 2. Separating additional data from metadata
> >>>>>>>>>
> >>>>>>>>> This would remove a lot of ambiguity and creates a clear order
> of assertion. It also seems to match the Wikidata data model.
> >>>>>>>>>
> >>>>>>>>> Example:
> >>>>>>>>>
> >>>>>>>>> :LizT :starredIn :JaneEyre
> >>>>>>>>>  {
> >>>>>>>>>      :role :HelenBurns,
> >>>>>>>>>      :pay-USD 10000,
> >>>>>>>>>  }
> >>>>>>>>>  {|
> >>>>>>>>>      :statedBy :Bob,
> >>>>>>>>>      :statedIn :Wikipedia,
> >>>>>>>>>  |}
> >>>>>>>>>
> >>>>>>>>> 3. Simple, compound, and complex statements
> >>>>>>>>>
> >>>>>>>>> Taking inspiration from linguistics, there could be four
> different types of statements:
> >>>>>>>>>
> >>>>>>>>> 1. Simple statement
> >>>>>>>>> 2. Compound statement
> >>>>>>>>> 3. Complex statement
> >>>>>>>>> 4. Compound-complex statement
> >>>>>>>>>
> >>>>>>>>> Simple statement (binary relationship):
> >>>>>>>>> S R O T1 T2 SB C
> >>>>>>>>>
> >>>>>>>>> Compound statement (graph):
> >>>>>>>>> {
> >>>>>>>>>  S R O T1 T2 SB C,
> >>>>>>>>>  S R O T1 T2 SB C,
> >>>>>>>>>  S R O T1 T2 SB C,
> >>>>>>>>> }
> >>>>>>>>>  T1 T2 SB C
> >>>>>>>>>
> >>>>>>>>> Complex statement (n-ary relationship):
> >>>>>>>>> S R O T1 T2 SB C
> >>>>>>>>>  {
> >>>>>>>>>      R O T1 T2 SB C,
> >>>>>>>>>      R O T1 T2 SB C,
> >>>>>>>>>  }
> >>>>>>>>>
> >>>>>>>>> Compound-complex statement (n-ary relationship):
> >>>>>>>>> {
> >>>>>>>>>  S R O T1 T2 SB C,
> >>>>>>>>>  S R O T1 T2 SB C,
> >>>>>>>>>  S R O T1 T2 SB C,
> >>>>>>>>> }
> >>>>>>>>>  T1 T2 SB C
> >>>>>>>>>  {
> >>>>>>>>>      R O T1 T2 SB C,
> >>>>>>>>>      R O T1 T2 SB C,
> >>>>>>>>>  }
> >>>>>>>>>
> >>>>>>>>> This creates consistency, and makes it easy to reason about the
> temporal/spatial validity of any graph.
> >>>>>>>>>
> >>>>>>>>> The existing RDF-Star "<<" and ">>" delimiters could be applied
> to statements of any type to say that a statement was "neutrally asserted",
> as I think Pat has described it before. Maybe for completeness, and based
> on something Pat published, other delimiters could be created that would
> mean "negatively asserted", something like "<!" and "!>" for example.
> >>>>>>>>>
> >>>>>>>>> The existing RDF-Star "{|" and "|}" delimiters could be applied
> to statements of any type to add metadata. The example in Section 2 of this
> email is an example of a complex statement with metadata.
> >>>>>>>>>
> >>>>>>>>> And I'm not sure, but it seems that nesting statements could be
> a general solution to contexts, the deepest nested statements would be in
> the most specific contexts. I haven't examined it properly though.
> >>>>>>>>>
> >>>>>>>>> If you've made it here thanks for reading! If you need more
> examples please ask and I'll do my best. I love everything done so far, I
> just want to bounce around these additional ideas with the hope that
> they're constructive. Please reply with any feedback at all, good and bad,
> it's all welcome!
> >>>>>>>>>
> >>>>>>>>> Regards
> >>>>>>>>> Anthony
> >>>>>>>> <OpenPGP_0x9D1EDAEEEF98D438.asc>
> >>>>>>>
> >>>>>> <OpenPGP_0x9D1EDAEEEF98D438.asc>
> >>>>>
> >>>>
> >>>
> >>
> >
>
>