Re: [xdi] CORRECTED Minutes: XDI TC Telecon Thursday 1-2:00PM PT2010-12-09

["Giovanni Bartolomeo" <giovanni.bartolomeo@uniroma2.it>]

Sorry Drummond, still some confusion I think..

>>> Giovanni pointed out that it one key semantic difference is the scope of
>>> the
>>> assertion about the property. In both diagram, the scope of the property
>>> +age is =abc. On the left diagram the scope of the property $d of the
>>> property +age is strictly within the context of =abc. On the right
>>> diagram,
>>> the scope of property $d is strictly in the context of =abc+age, i.e.
>>> exactly  =abc's +age (and not e.g. =xyz+age).
>>>
>>>
>> In the RIGHT diagram, the scope of the property +age is =abc; in the LEFT
>> diagram, the scope of the property +age$d (and NOT +age) is =abc.
>>
>> Do you agree?
>>
>
> Giovanni, you are correct. Ironic that we were all staring at the minutes in
> Idearpad and no one saw this. Good catch!
>
> I'll issue corrected minutes.
>
> =Drummond
>

I propose a simpler correction:

"Giovanni pointed out that it one key semantic difference is the scope  
of the assertion about the properties.

On the LEFT diagram, the scope of both properties +age and +age$d is =abc.
On the RIGHT diagram the scope of the property +age is =abc; and the  
scope of the property $d is =abc+age."

Is this ok with you?

Kind Regards,
Giovanni

Def. Quota "Drummond Reed" <drummond.reed@xdi.org>:

> SEE THE CORRECTION MARKED ^^^^^^^^^^ BELOW
>
> ---------- Forwarded message ----------
> From: Drummond Reed <drummond.reed@xdi.org>
> Date: Thu, Dec 9, 2010 at 8:04 PM
> Subject: Minutes: XDI TC Telecon Thursday 1-2:00PM PT 2010-12-09
> To: OASIS - XDI TC <xdi@lists.oasis-open.org>
>
>
> Following are the minutes of the unofficial telecon of the XDI TC at:
>
> Date:  Thursday, 09 December 2010 USA
> Time:  1:00PM - 2:30PM Pacific Time (21:00-22:30 UTC)
>
> ATTENDING
>
> Giovanni Bartolomeo
> Markus Sabadello
> Drummond Reed
> Joseph Boyle
> Michael Schwartz
>
>
> THE GOTOMEETING FOR TODAY IS:
>      https://www2.gotomeeting.com/join/969244355
>
> THE IDEARPAD LINK FOR TODAY IS:
>      http://xdi.idearpad.org/15
>
> Please try to preface each of your comments with your name so the
> transcription into the minutes is easier.
>
>
> 1) REVIEW OF XDI GRAPH PATTERNS
>
> The entire topic for the call was the patterns that have been posted at:
>
>   http://wiki.oasis-open.org/xdi/XdiGraphPatterns
>
> In particular, Giovanni has posted several alternative patterns, and
> Drummond has posted the proposed link contract pattern he has been working
> on.
>
> We began by walking through the page reviewing Giovanni's comments.
>
> His first comment was about using self-referential arcs to indicate
> comments. The self referential arc for Giovanni violates the mereological
> principle he has followed to assign semantics to the XDI graph [discussed in
> ref-minutes]
>
> Drummond notes that there is no disagreement about what a synonym is, and
> Giovanni's suggestion is intended to make it clear there's no semantic
> difference.
>
> # ACTION: Drummond to suggest a way to express synonyms for a root context
> node.
>
> Giovanni's second comment was about the assertion of authority for an XDI
> document.
>
> Drummond replied that he has been thinking about a stronger mechanism. He
> believes that they are two separate issues: 1) how to express synonyms for
> the root node, and 2) how to assert authority for an XDI document. He
> believes the latter is better handled by a link contract.
>
> We talked about how XDI discovery works. Drummond said his view of XDI
> discovery is that there is one logical global XDI graph, and then many
> physical instances of that graph, and that XDI discovery is starting with
> some known instance and making XDI $get requests from that graph to discover
> the URI of the instance that has the target portion of the graph you are
> trying to reach -- and iterating this process as needed, just like in DNS.
>
> Giovanni said that he believes that there is a  similarity, from a logical
> PoV, between discovering those instances in the global graph and
> discovering, for example, a subgraph in a reification sentence (e.g.
> discover subject =bob in the assertion =alice/+say/(=bob/+age/"31") )
>
> # ACTION: Drummond to add illustration/explanation of how he sees XDI
> discovery working.
>
> We discussed the use of the word "fractal" with regard to the XDI graph. We
> agreed that each instance of the graph is a copy of the same structure of
> the whole -- and it that sense it fits -- but that each instance is not a
> copy of the content of the whole -- and in that sense it doesn't fit,
> because in that sense it is not self-similar.
>
> ********
> The next discussion was about the Single-Valued Property Pattern. Giovanni
> proposed a different pattern, labelled on the wiki page as "proposal".
>
> He walked us through his rationale for the proposed pattern, which is also
> what came out of the Whistler retreat. It contextualizes the property +age
> in =abc, subjectifies it and declares one of its properties ($d) in a
> similar way as you assign a value to property +age of subject =abc.
>
> Drummond pointed out the core semantic problem with Giovanni's proposal. To
> assert a datestamp on a +age property, you must define "a property on a
> property". That is what we are trying to model in the Single-Valued Property
> Pattern diagrams. In order to model a property on a property, the "subject"
> of that metadata statement must be a property. In the diagram on the left,
> the "subject" of the $d extension is =abc/+age. =abc/+age is a property of
> =abc. Whereas =abc+age is not a property, but another XDI subject.
>
> Giovanni pointed out that it is not necessary to be a property. In RDF, you
> can use a property as a subject when you have to state something on the
> property itsef (examples include rdfs:domain and rdfs:range).
>
> Moreover, Giovanni said that the left graph is asserting something slightly
> different than the right graph.He tried to figure out another example.
> Property --> +color, property on a property --> +hue, i.e. +color+hue
>
> =mycat/+color+hue/+grey
> =mycat+color/+hue/+grey
>
> +color+hue exists even if =mycat is not existing (you could even have
> +color+hue as subject in another statement, assumed there is something to
> say about +color+hue). You can apply then the first assertion (asserted in
> the left graph); in the second statement, you suppose there exists a cat
> (=mycat), and it has a color; then you state some property on =mycat's
> color. Open issue: could we have similar thoughts when we think about
> +age$d?
>
> ^^^^^^^^^ "left" AND "right" WERE ORIGINALLY REVERSED IN THE PARAGRAPH
> BELOW. THE VERSION BELOW IS NOW CORRECTED ^^^^^^^^^
>
> Giovanni pointed out that it one key semantic difference is the scope of the
> assertion about the property. In both diagrams, the scope of the property
> +age is =abc. On the right diagram the scope of the property $d of the
> property +age is strictly within the context of =abc. On the left diagram,
> the scope of property $d is strictly in the context of =abc+age, i.e.
> exactly  =abc's +age (and not e.g. =xyz+age).
>
> Joseph brought up that if there is going to be any semantics involved with
> trailing slashes, they should be modelled as nodes.
>
> 2) NEXT CALL
>
> We agreed that we would hold calls both next Thursday (although Drummond may
> possibly have a conflict) and Thursday the 23rd, and probably not hold one
> on Thursday the 30th (to give us a week off between Christmas and New
> Years).
>
>
> ------------
> ONGOING ISSUES LIST
>
> Each of these is a candidate for the agenda for future calls.
>
> * PROPOSED CONSTRUCTS/OPERATORS FOR XDI
>
> Discuss the following wiki page originally posted by Giovanni:
>
>   http://wiki.oasis-open.org/xdi/XdiNewFoundation
>
> * DICTIONARY STRUCTURE
>
> Mike would like an example of the PDX dictionary as soon as we can do it.
>
> *   EQUIVALENCE SEMANTICS
>
> Close on whether we need an additional $ word   that is the equivalent
> of Higgins Personal Data Model (PDM)  semantics   of h:correlation,
> which is not as strong as $is.
>
>       http://lists.oasis-open.org/archives/xdi/201006/msg00036.html
>
> * COOL URIS
>
> Continue previous discussion about the use of standard RDF URIs in XDI:
>
>   http://lists.oasis-open.org/archives/xdi/201006/msg00023.html
>



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