Model group ambiguities

[Daniel B. Austin]

Helmut,

    SGML content models can be reduced to deterministic forms in all cases,
but
the techniques for doing so can be difficult, and the effort involved
extensive. While
any SGML content model can be rewritten to conform to the XML specification,
the result may be quite lengthy. A parser written to do this would be a
complex
undertaking.
    You can find information regarding SGML & XML content models here:
http://www.cs.helsinki.fi/~kilpelai/C-1998-12.html .
This paper by Pekka Kilpelainen at Helsinki U. is a rigorous explication of
the mathematics involved.

Regards,

D-
****************************************************************************
****
Daniel Austin, Director of Development, Creative Services, CNET
daniela at cnet.com    415-395-7800 x1438
"To change the old into the new, and the shapes of things to come..."





-----Original Message-----
From: Helmut Lutzenberger <lutzenbe at informatik.tu-muenchen.de>
To: <xml-dev at ic.ac.uk>
Date: Tuesday, July 28, 1998 9:42 AM
Subject: Model group ambiguities


>Hi,
>
> I read something about model group ambiguities, saying things like:
>(item?, item) are ambiguous and are therefor not parseable by an
>XML-parser.
>
>My question is now; model groups are regular expressions and every
>regular
>expression is equal to a nondetermenistic automat and with
>Myhill-Nerode it
>is possible to build an determenistic automat equal to the
>nondetermenistic
>one. So I thing it should be possible for the XML-Parser to eliminate
>such
>ambiguities automatically, without too much trouble. Or am I wrong?
>
>-Helmut
>
>--
>Helmut Lutz Lutzenberger
>Phone: +49-89-68 29 17
>Email: lutzenbe at informatik.tu-muenchen.de
>
>
>xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at ic.ac.uk
>Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/
>To (un)subscribe, mailto:majordomo at ic.ac.uk the following message;
>(un)subscribe xml-dev
>To subscribe to the digests, mailto:majordomo at ic.ac.uk the following
message;
>subscribe xml-dev-digest
>List coordinator, Henry Rzepa (mailto:rzepa at ic.ac.uk)
>
>


xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at ic.ac.uk
Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/
To (un)subscribe, mailto:majordomo at ic.ac.uk the following message;
(un)subscribe xml-dev
To subscribe to the digests, mailto:majordomo at ic.ac.uk the following message;
subscribe xml-dev-digest
List coordinator, Henry Rzepa (mailto:rzepa at ic.ac.uk)