Hi Bill,
I would prefer that you discuss any membership category
pricing with Scott McGrath – individuals must be*employed* by the organization,
not members of, in order to qualify under an organization’s membership. For
instance, STC is a member (Society of Technical Communicators). They have a
handful of employees but thousands of members. They are allowed 2 participants –
either actual employees or designated members. It’s all tied to who owns your
IPR. Please do not make any claims about who is/isn’t able to participate.
Remember, OASIS’ only source of income is member dues.
Regards,
Mary
From: Barnhill, William
[USA] [mailto:barnhill_william@bah.com]
Sent: Friday, April 25, 2008 8:37 AM
To: Drummond Reed; xdi@lists.oasis-open.org
Subject: [xdi] Membership #s and costs
Hi All,
Drummond raised a question on the call the other day regarding what the max
numbers and costs for each level of OASIS participation are. You can find
that information buried in the OASIS site at the following URL:
http://www.oasis-open.org/join/categories.php#individual
My guess is that any Open Source foundation level org such as OpenID will have
100+ member, and given that the cost per year is $7500 for contributor level.
The good news is that the highest contributor category is 500+ people and is
only $500 more ($8k). If you can get OASIS to accept an Open Source
organization as an Association then they can be grouped into the non-profit etc
grouping, and the cost for contributor level goes down to $1100.
I'd like to be engaged in talks with them regarding joining OASIS as I can
grease the wheels while I'm on the TAB and get easier answers to questions
(above info case in point). Once we get to a good point (should be quickly) we
can talk to Jamie and Eduardo about getting them declared an Association.
Thanks,
Bill
-----Original Message-----
From: Giovanni Bartolomeo [mailto:giovanni.bartolomeo@uniroma2.it]
Sent: Thu 4/24/2008 6:09 AM
To: Drummond Reed; xdi@lists.oasis-open.org
Subject: [xdi] XDI dictionary, reasoner...
Hello Drummond, All,
as for last week's request, I'm reintroducing this issue. After receiving your
answer, I tried to figure out how to prove that two XDI RDF statements
=giovanni+home+phone/$type$xsd$string/
=giovanni/+home+phone/
does identify the same node. In order to recall the whole issue, which is
now also on the wiki thanks to Drummond, <http://wiki.oasis-open.org/xdi/XdiReasoners>
http://wiki.oasis-open.org/xdi/XdiReasoners
I report hereafter the whole message, at the end my elaborations:
********** Drummond replies **********
I am so glad someone finally asked this question in black and white - I have
been thinking about this issue of "XDI expressivity" for months now
given the fundamental capabilities of XDI RDF. Forgive me for providing an
extended answer, but I think the question can be so revealing about the power
of XDI RDF.
First, to answer your question right up front, "Do those three XDI
addresses identify the same literal node?", my answer is: "You cannot
know deterministically without reference to the XDI dictionaries used by the
statements."
The reason is that the three statements represent three different paths through
the XDI RDF graph, and as you pointed out, each path represents different
semantics. So you you really have to drill all the way down into the graphs,
and the statements represented by each graph, in order to answer your question.
To do this, let's start by looking at the three graphs visually in X3 Simple
(one reason I love X3 Simple is that it lets you see the visual pattern of the
graph while at the same time seeing the addresses).
#1
=giovanni+phone+home
$type$xsd$string
"+39 06 4451843"
#2
=giovanni
+phone+home
"+39 06 4451843"
#3
=giovanni+phone
+home
"+39 06 4451843"
Now, let's "fully explode" each of these into ALL the XDI statements
they represent.
#1 (5 statements)
=giovanni
$has
+phone
=giovanni+phone
$has
+home
$type
$has
$xsd
$type$xsd
$has
$string
=giovanni+phone+home
$type$xsd$string
"+39 06 4451843"
#2 (3 statements)
=giovanni
$has
+phone+home
+phone
$has
+home
=giovanni
+phone+home
"+39 06 4451843"
#3 (2 statements)
=giovanni
$has
+phone
=giovanni+phone
+home
"+39 06 4451843"
Isn't it fascinating that the first graph represents five statements, the
second three, and the final one only two?
In any case, all three options here (plus more - see below) appear to be
completely valid chains of XDI statements between the XDI subject =giovanni and
the XDI literal "+39 06 4451843". But none of them asserts exactly
the same semantics (the only way to do that would be to use XDI synonyms, i.e.,
$is statements). However using an XDI reasoner and an XDI dictionary (which
itself is just a set of XDI statements comprising definitions), you could
verify that according to that dictionary, all these statements identify the
same literal node.
In fact the dictionary is pretty short. Here it is:
+phone
$is$a
<--1-->
+
$type$xsd$string
$has
<--2-->
+home
$a$has
<--3-->
+home
$has$a
<--4-->
+home
$a$has$a
<--5-->
+home
+home
$is$a
<--6-->
+
$has
<--7-->
+phone
$a$has
<--8-->
+phone
$has$a
<--9-->
+phone
$a$has$a
<--10-->
+phone
$type
$has
$xsd
$type$xsd
$has
$string
As short as it is, the semantics represented by those statements - while
crystal clear from a pure XDI semantics point-of-view - represent a surprising
range of grammatical relationships a human POV. Roughly translated to English,
the first ten statements say:
1) A phone is both a subject (noun) and a label for a type of data (typically
called a "phone number", but often abbreviated in English as just
"phone").
2) A phone can have a home, i.e., as a noun, it can have a possessive
relationship with another noun, home.
3) A phone is something a home can have (possessive relationship).
4) A phone has an attribute of home.
5) Phone is an attribute of a home.
6) Home is a subject.
7) A home can have a phone (possessive relationship - inverse of #3).
8) A home is something a phone can have (possessive relationship - inverse of
#2).
9) A home has an attribute of phone (inverse of #5).
10) Home is an attribute of a phone (inverse of #4).
Armed with that dictionary, an XDI reasoner can quickly prove that all the
following XDI statements identify the same literal:
=giovanni+phone+home/$type$xsd$string/
=giovanni+home+phone/$type$xsd$string/
=giovanni/+home+phone/
=giovanni/+phone+home/
=giovanni+phone/+home/
=giovanni+home/+phone/
However, if you remove any of those XDI dictionary statements, some of the
above are no longer provably true. For example, if you remove the statements:
+phone
$has
$home
+home
$a$has
+phone
Then you could no longer prove that the following two statements identify the
same XDI object as the rest:
=giovanni+phone+home/$type$xsd$string/
=giovanni/+phone+home/
They MIGHT identify the same literal as the rest, but now you have nothing you
can prove that with.
There's much more I'd like to say about this simple dictionary, but I'm out of
time. However I encourage everyone who is interested to study it closely. To
test your knowledge, here's a quiz question:
"Given the
dictionary above, how can you prove that it is valid for the XDI object of all
six statements to be a literal string?"
=Drummond
Now, I think the most important part to understand is related to the semantics
underlying the dictionary sentences:
+phone
$has
<--2-->
+home
$has$a
<--4-->
+home
which in English means
2) A phone can have a home, i.e., as a noun, it can have a possessive
relationship with another noun, home.
4) A phone has an attribute of home.
$has, according to XDI RDF model v9, is aggregation, meaning that
Any two XDI subjects with a $has relationship can be concatenated into a single
XRI representing this relationship.
Thus +phone+home is the way how aggregation is expressed.
Whereas $has$a is defined as a composition. The object in the RDF statement is
therefore an "attribute" belonging to the subject.
Example similar to the one in XDI RDF v9: =giovanni/$has$a/+hair+color; thus
=giovanni/+hair+color/+black should be a valid XDI RDF statement,
expressing composition.
Quoting from wikipedia, difference between aggregation and composition:
Aggregation differs from ordinary composition in that it does not imply
ownership. In composition, when the owning object is destroyed, so are the
contained objects. In aggregation, this is not necessarily true. For example, a
university owns various departments (e.g., chemistry), and each department has
a number of professors. If the university closes, the departments will no longer
exist, but the professors in those departments will continue to exist.
Therefore, a University can be seen as a composition of departments, whereas
departments have an aggregation of professors. In addition, a Professor could
work in more than one department, but a department could not be part of more
than one university.
Now, I tried to work out a formal proof using the assertions 1)-10) but I
failed in proving
that all the following XDI statements identify the same literal:
...
=giovanni+home+phone/$type$xsd$string/
=giovanni/+home+phone/
...
Probably I'm missing something (probably some underlying semantics), however,
can you give some hints? Maybe we can work out the prove once for all and
report this in the wiki/deliverable, as reference?
Thanks,
Giovanni
At 01.32 24/04/2008, Drummond Reed wrote:
4) TECH TOPIC: XDI DICTIONARY AND XDI REASONER
On last week's call Giovanni requested that our tech topic this week be the
XDI dictionary and XDI reasoner discussion we started on the list. Wikipedia
has a good article on semantic reasoners:
<http://en.wikipedia.org/wiki/Semantic_Reasoner>
http://en.wikipedia.org/wiki/Semantic_Reasoner
Drummond created a wiki page to capture the email thread for further
discussion:
<http://wiki.oasis-open.org/xdi/XdiReasoners>
http://wiki.oasis-open.org/xdi/XdiReasoners
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