- From: Jim Hendler <hendler@cs.umd.edu>
- Date: Wed, 13 Nov 2002 22:17:44 -0500
- 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 UTC