[SCL] Representing constraints that go beyond EBNF

[Murray Altheim]

John F. Sowa wrote:
> Murray,
> 
> That was the whole point of my previous note (copy below):
> 
> MA> I'm guessing I'm missing something here. What is it that EBNF
>  > can't provide?
[...]

Fair enough. As I said, I've been lax in keeping up with the
conversation this week.

I would note one thing regarding a statement you made, which while
not atypical, deserves comment:
[...]
 > Re Schematron:  I followed the pointer to the Schematron tutorial, which
 > led me to other pointers to XMLCL (XML Constraint Language).  Both of
 > those languages seem to be hacked up subsets of Horn clauses written
 > by people whose knowledge of logic is questionable.
 >
 > My major concern about Schematron or XMLCL is that I have no confidence
 > in their logical foundations, and I seriously doubt that their rule
 > languages support the kind of recursion one would like to use for
 > checking arbitrary nests of quantifiers.

The people who developed or had major input into Schematron include
Rick Jelliffe, Uche Ogbuji, Makoto Murata, James Clark and many
others. As you may know, most of these people's credentials are without
question. Rick's, Murata-san's, and Uche's reputations are about as
good as you find in IT, James Clark obtained Class I honours in
mathematics and philosophy at Oxford and is considered (certainly by
myself and many others I know) one of the most intelligent people in
the industry, with a wide understanding of language and other issues.
Murata Makoto and James Clark singlehandedly created RELAX-NG (each
providing one half of the acronym). None of these people could be
accused of having any deficiency in their knowledge of logic.

Would you actually state that to their face? I doubt it. It's easy
to deride someone in email, but they've accomplished something you've
yet to do: they've built something extremely solid and functional
that will become an ISO standard, fairly soon too. While it may not
be suitable for our purposes here (I can't evaluate that), I don't
think it deserves the kind of backhanded criticism you've given it.
They're all also very gracious and generous people -- if you were to
describe the problem to either Rick, Uche, Murata-san, or James,
they'd likely be quite happy to help you figure out if it *did* fit
the bill. It might very well, and you might be surprised that they
do know what the hell they're doing, and that the field of markup
isn't *entirely* full of ignorant hacks. My experience has been
exactly the opposite.

Murray

...........................................................................
Murray Altheim                         http://kmi.open.ac.uk/people/murray/
Knowledge Media Institute
The Open University, Milton Keynes, Bucks, MK7 6AA, UK                    .

   Q: So exactly how is Ahmad Chalabi different from Manuel Noriega?

      http://www.nationalreview.com/comment/comment-singer062002.asp
      http://www.iraqinews.com/people_chalabi.shtml
      http://truthout.org/docs_03/041103F.shtml

   A: One speaks fluent Arabic, the other Spanish.

     "Noriega took refuge in the Vatican embassy, where US troops played
      hard rock music until Noriega surrendered on January 3, 1990."
      http://www.nationmaster.com/encyclopedia/Manuel-Noriega
      http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB2/nsaebb2.htm#3a
      http://www.addictedtowar.com/panama.htm