Minutes: XDI TC Telecon Thursday 1-2PM PT 2009-02-19

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

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

Date:  Thursday, 19 February 2009 USA
Time:  1:00PM - 2:00PM Pacific Time (21:00-22:00 UTC)

ATTENDING

John Bradley 
Markus Sabadello
Drummond Reed
Giovanni Bartolomeo


AGENDA

Reminder - please join the Jabber chat room if you can - see the
instructions from Bill at:

	http://lists.oasis-open.org/archives/xdi/200902/msg00010.html


1) CONTINUED DISCUSSION OF +X/+Y/+X+Y

See Giovanni's message at:

	http://lists.oasis-open.org/archives/xdi/200902/msg00025.html

Today's discussion revolved around the relationship of classes and instances
when the $has predicate is the relationship. We discussed that you can have
a $has relationship between a class (+ball) and an instance (*foo), between
an instance (=drummond) and a class (+ball), between two instances
(=drummond and *foo), or between two classes (+ball and + color). Or any
combination:

+ball*foo
=drummond+ball
=drummond+ball*foo
=drummond*foo
+ball+color
=drummond+ball+color*foo

So the question was: how can an XDI processor unambiguously determine
whether the subject is a class or an instance? John proposed the answer that
it is based on the delimiter of the final XRI subsegment in the XRI
identifing the XDI subject. The global context symbols + and $ represent
classes; all other delimiters represent instances.

It was agreed that this rule fit the pattern than when +x/$has/+y,
+x+y/$is$a/+y. It looks promising; we should all cogitate on it.

We also discussed Giovanni's question about whether +x/$has/+y can produce
the new XDI RDF subject +x+y without requiring that it produce the XDI RDF
statement +x/+y/+x+y?

Drummond asked that for +x/$has/+y, if the relationship is not +x/+y/+x+y,
then what is the relationship between +x and +x+y? This is something that
needs further work.


2) $SET PROPOSAL

See Markus' message at:

	http://lists.oasis-open.org/archives/xdi/200902/msg00024.html

Amongst those on the call, there was general support that a $set operation
seemed like an optimization that made sense. We should begin using it in
experimental implementations and see if it raises any issues.


3) NEXT CALL

Next Thursday at the regular time, 1-2PM PT (21:00-22:00 UTC).