Re: Agenda for 23 January 2013

Partial regrets. I have to accompany someone to a medical appointment. I will try to call in by cell, but I wont have IRC or an open computer, so voice only. And I will probably be late. 

Regarding the semantic issue. The options we have to choose between are 

(1) leave it as it is. The 2004 semantics does not treat an ill-formed literal as an error by itself, but it is inconsistent to assert that it is a LiteralValue or that it is the range of the relevant datatype. 

(2) (with a small modification to the model theory) we can make it be that any triple containing an illformed literal is false, so that any RDF graph containing such a literal is inconsistent. 

In both cases, this only applies when we talking about the built-in datatypes, or we are restricted to D-interpretations with D containing the relevant datatype. 

The pros and cons seem to be that (1) requires least change, but (2) means that Richard does not have to explain the difference between inconsistent and ill-typed. 

We can make the semantics work either way. Some of the standard entailments will need to be explained slightly more carefully in case (2); they are still valid, but only because the antecedent is false in some cases. For example, the entailment

sss ppp "foo"^^:type .


sss ppp _:xxx .

is valid in both cases, but in case (2), the conclusion might well be false, when the string "foo" is not in the lexical space of :type.


On Jan 21, 2013, at 8:39 PM, David Wood wrote:

> Hi all,
> The agenda for Wed, 23 Jan 2013 is available at:
> Chair: David Wood
> Scribe: Richard Cyganiak
> Alternate: Sandro Hawke
> This week, we will look at the remaining Semantics issue and some open issues related to clean up tasks.
> Regards,
> Dave
> --

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Received on Wednesday, 23 January 2013 06:03:24 UTC