Re: Non-deterministic content model

[Robin Cover <robin@isogen.com>]

On Thu, 14 Jun 2001, Marcus Carr wrote:

> 
> Derek Denny-Brown wrote:
> 
> > It is provable that _every_ non-deterministic content model can be
> > converted to a deterministic content model.  The trick is basically to
> > manually 'unroll' the content model.
> 
> Sam Willmott from OmniMark released a white paper on content model algebra
> in the early nineties. He concluded that there was only one content model
> that cannot be disambiguated and I have yet to see proof to the contrary.
> The model is:
> 
>    (x, (y, x)*, y?)
> 
> Feel free to bang some grey matter against it...

Some useful references might be found in:

"SGML/XML Notion of Ambiguity (non-deterministic content models)"
http://www.oasis-open.org/cover/topics.html#ambiguity

Best wishes,

Robin Cover

PS  I'm uncertain whether OmniMark's paper (by Sam Wilmott) is still
available online.  If not, the papers of Anne Brueggemann-Klein will
probably suffice.  If not, also register a note of irony: SGML/XML
as an "enabling technology" does NOT enhance information longevity if
documents encoded in SGML/XML are treated with indifference by
system administrators and marketing goons who perceive no value in
technical information (Wilmott's paper was a monument).  For
Anne's research, see pointers in:

http://xml.coverpages.org/bib-ab.html#brugCompiler

and environs.  If anyone from OmniMark is subscribed to XML-DEV, perhaps
s/he might offer clarification on the status of the Wilmott paper
on "Content Model Algebra."

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