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RE: Semantics in WSDL-S ?!

From: <jeff@inf.ed.ac.uk>
Date: Mon, 21 Nov 2005 19:11:33 +0000
Message-ID: <1132600293.43821be553873@mail.inf.ed.ac.uk>
To: public-sws-ig@w3.org

Quoting "Shi, Xuan" <xshi@GEO.WVU.edu>:

> For example, WSDL interface:
>
> Function intersect (String Polygon1, String Polyon2): String Polygon3.
>
> The meaning of this function depends on the purpose of your action.

It often seems to me that arguments like that are in effect saying
that programming languages can't be used to write programs because
it's too unclear what procedure calls mean.

> Clearly, there's a lot you can't say in WSDL. What it does well is to
> describe the service _signature_ in terms of the operations available
> through one or more service interfaces. Like you say it doesn't capture
> any of the 'meaning' as you describe above, which includes composition,
> inputs and outputs (and their types).

It looks to me like the description of "intersect" above does
give the inputs and outputs and their types.  The types all
happen to be String.  Or am I misunderstanding the notation?

> But this is a different question
> as to whether it is 'semantic' or not. WSDL 2.0 now has an RDF mapping
> that furnishes it with a model theory.

_A_ model theory, yes; but pretty much anything can be mapped to
RDF.  I'm not sure that gives it a very interesting or
useful semantics.  Typically there will be a bunch of URIs
whose meaning (in the ordinary sense) is given by some natural-
language text.  For example, to discover what Dublin Core
"creator" means, you have to consult a document such as this
one:

  http://dublincore.org/documents/dces/

or read a comment in the RDF schema.

Using RDF lets you perform some inferences (I like the comment
that the semantic web was really the logical web), but so do
the type systems in programming languages.  Description Logic
makes some things easier, but others more awkward.

-- Jeff
Received on Monday, 21 November 2005 19:11:40 GMT

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