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in line literal semantics

From: Jeremy Carroll <jjc@hpl.hp.com>
Date: Sun, 8 Sep 2002 22:29:53 +0200
To: w3c-rdfcore-wg@w3.org
Message-Id: <200209082229.54027.jjc@hpl.hp.com>



In one camp, that has been quite quiet of late, we have those who argue that 
inline literals should be self denoting.

In another, there are those, (some of whom believe the argument has been won), 
who argue that inline literals denote something else, which might be made 
clear elsewhere.

Then there also a few voices, myself and Graham, at the last telecon, arguing 
for minimalism.

We have seen the tidiness vs untidiness debate as one without a middle ground.

The point of this message is to propose it. (or rather to remind the group of 
its existence).

Middle ground:
============
From datatyping part 1:
  Explicit data values in the graph are self denoting.

From Valentines day MT (VMT)
http://www.w3.org/TR/2002/WD-rdf-mt-20020214/
  Other literals are syntactically untidy.
  Literal semantics depends on a function XL mapping lteral nodes to literal 
values.
  Nothing is said about whether XL induces a function or not on the literal 
labels. i.e. this does not rule out tidy semantics.

Moreover, consider the crucial tidiness entailments.

<a> <foo> "literal" .
<b> <bar> "literal".

this does not entail

<a> <foo> _:b .
<b> <bar> _:b .

(in the VMT)

However, this is not because of untidy semantics, but merely because the first 
triple by itself is not entailed.
i.e.
<a> <foo> "literal" .

does not VMT-entail

<a> <foo> _:b 

(bnodes don't match literals in the Valentines day MT).


Thus, if we choose the Valentines day MT, we are not ruling out RDF2 choosing 
tidy semantics.
We, are old and tired, we already have agreed enough to meet our charter. We 
should postpone work on the semantics of inline literals for a new and fresh 
working group.

========

Obviously, I have been an advocate of untidiness for a while; if the grouo has 
consensus to go with untidiness, then I clearly would be in favour.
However, I would also be very surprised.

If any of the group cannot live with Part 2, but could accept some sort of 
compromise of the sort outlined above, then they would get my support.

Another way to go would be for us to collectively downgrade the tidiness 
issue. My take, is that with the values in the graph, the decision for tidy 
or untidy is much less pointed. Although I would value the debate, I believe 
my position has changed from "cannot live with tidy" to simply a preference 
for untidy.
If we all can downgrade our previously strong opinions then a debate and 
asimple majority decision would suffice.

Jeremy
Received on Sunday, 8 September 2002 20:32:58 EDT

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