Minutes: XDI TC Telecon Thursday 8-9AM PT 2008-01-24

["Drummond Reed" <drummond.reed@cordance.net>]

Following are the minutes for the unofficial telecon of the XDI TC at:

Date:  Thursday, 24 January 2008 USA
Time:  8:00AM - 9:00PM Pacific Time

Event Description:
Weekly unofficial call of the XDI Technical Committee.

ATTENDING

Victor Grey 
John Bradley
Giovanni Bartolomeo 
Markus Sabadello
Drummond Reed 
Fen LaBalme


AGENDA

1) DOLLAR WORD PROPOSAL AND XDI $ DICTIONARY DISCUSSION

Giovanni Bartolomeo submitted a proposal for additional XDI $ words:

http://www.oasis-open.org/apps/org/workgroup/xdi/download.php/26914/Draft-Co
ntrib-OASIS-XDI-dollar-words.pdf

* Giovanni introduced his paper by explaining the value of having $ words
for numbering, order, and equivalence. 

* $num can handle the number concept and be used to express cardinality and
multiplicity. 

* Markus asked if $num is always used in conjuntion with $has predicate, or
if there would be other uses? Giovanni said it would also be useful
standalone.

* $equals, as explained in the paper, expresses a different equivalence
relationship that $is. $is expresses equivalance of XDI subject nodes (that
themselves are "valueless") i.e.,  that they represent the same target
resource. $equals would assert equivalence of values.

* $equalsOrGreater and $greater enable ordering relationships between
values. For example, this enables accurate description of multiplicity. 

* Fen asked, in the example of a cardinality expression, whether a
cardinality error would be captured by conformance with the XDI data model
or by an application or XDI database that was enforcing this rule. Giovanni
said that his team needed to enforce some of these rules at the database
level.

* Drummond suggested the following distinction: 1) syntactic rules, which
can be validated by the X3 ABNF; 2) grammatic rules, which apply to the
metamodel predicates, the operations predicates, and any other core XDI data
model validation, and 3) semantic rules, which are are domain specific.

* John said that ooTao has created a set of $ words as part of the $op
space. 

* Drummond suggested that we use the wiki for discussion of $ word
proposals, since that would give us a forum for referencing, collaborating,
and discussing them pre-spec.

* Victor seconded the use of the wiki, and said that the $ space, once
worked out, should be very stable and not change very often. Drummond
likened it to the grammer of a language, which does not evolve much for the
same reason. Drummond urged the Einsteinian, "Simple as possible but no
simpler" dictum.

# GIOVANNI to submit a slight revision to his paper with corrections.

# JOHN to prepare a list of the $op words that ooTao is using.

# DRUMMOND to set up a page on the wiki to track $ words and send email to
the TC.


2) XDI MESSENGER

We ran out of time for Markus Sabadello to do a demonstration of his XDI
Messenger application, but he will demonstrate it on the next call (in two
weeks, see below). For anyone who wants to review it in the meantime:

	http://graceland.parityinc.net/xdi-messenger/XDIMessenger 


3) STATUS ON XDI RDF MODEL DOCUMENT UPDATE

Drummond, Markus, and Paul plan to submit an update to the XDI
RDF Model document (current version at
http://www.oasis-open.org/committees/download.php/25531/xdi-rdf-model-v7.pdf
) before the Higgins F2F meeting next week, where they will be doing a
presentation on XDI RDF and X3.


4) NEXT CALL

Due to the Higgins F2F, we will skip next week's call. The next call will be
8-9AM PT Thursday February 7tn.