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RE: MT for imports (was: Re: Imports Proposal)

From: Jim Hendler <hendler@cs.umd.edu>
Date: Wed, 13 Nov 2002 22:17:44 -0500
Message-Id: <p05111706b9f8c471027b@[10.0.1.2]>
To: Frank van Harmelen <Frank.van.Harmelen@cs.vu.nl>, www-webont-wg@w3.org

At 1:52 AM +0100 11/14/02, Frank van Harmelen wrote:
>I remain entirely baffled by all of this.
>
>As Jerome Euzenat wrote:
>
>>The timed web structure applies to ontologies exactly like it applies to
>>hyperlinks in html, xsl:include and xsl:imports in XSLT, etc.
>
>Of course, some advanced version of imports would depend on the 
>"timed web structure" (Massimo), but I cannot see how that should 
>stop us from providing something simple.
>
>Lots and lots of computer languages provide import-like things,
>varying from C to Scheme, and from LaTeX to XML. None of these have 
>any of the problems raised in the preceding discussion. Pat's 
>example of someone changing an imported file is common to all of 
>these, happily ignored by all of them, and rightly so, since it 
>doesn't seem to break any of them, the meaning and pragmatics of 
>these import constructions is entirely clear for all of them. If it 
>works for XML, why wouldn't it work for OWL?
>
>I can simply not imagine standing up in front of a crowd, proudly 
>explaining OWL, and having to admit that,... eh... no, well... 
>actually, in OWL you cannot import other people's ontologies...
>
>Frank.
>   ----


Frank - let me be clear, Dan and I are not arguing that we shouldn't 
have an imports mechanism, just that we shouldn't define it precisely 
at this time (and in a manner we may regret later).  The DAML 
solution was to provide imports, explain it in English, and 
essentially say that there was no formal semantics for it at this 
point.  I would be very happy for us to say the same.  What I believe 
is that our current proposed solutions are drastically different than 
the nice C, Fortran, etc. include statements, which DON'T have a 
formal semantics (and the new logic-based formal verification 
langauges currently don't allow imports as far as I can tell) - I'd 
like us to handle it like those languages do -- explain what we 
expect to happen, and leave it to the implementors to work out how -- 
once entailment tests entered the picture, I moved from in favor to 
against, and I remain there.
  I see POSTPONING this issue as being exactly the same as what 
DAML+OIL currently has - imports as magic syntax, that works just 
fine thank you and let's not screw around with it
  -JH
p.s. If the WG votes in favor of this crazy semantic approach to 
imports, may I make the friendly amendment that we rename it 
owl:includes, which does strike me as a better name.
-- 
Professor James Hendler				  hendler@cs.umd.edu
Director, Semantic Web and Agent Technologies	  301-405-2696
Maryland Information and Network Dynamics Lab.	  301-405-6707 (Fax)
Univ of Maryland, College Park, MD 20742	  240-731-3822 (Cell)
http://www.cs.umd.edu/users/hendler
Received on Wednesday, 13 November 2002 22:17:53 GMT

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