Re: Non-deterministic content model

[Jeni Tennison <mail@jenitennison.com>]

Hi Francis,

> Robin Cover wrote:
>> On Thu, 14 Jun 2001, Marcus Carr wrote:
>> >
>> > 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?)
>
> I'm trying to iterpret this interesting theory thread in the light of
> existing validation technologies.
>
> Taking the chess moves interpretation, the ambigous model above can be
> implemented in Schematron as:
>
[snip]
>
> Is it equally simple to implement this ambiguous model in other schema
> technologies?

RELAX NG doesn't require deterministic patterns; the following
schema should do it:

<element name="game">
   <element name="white" />
   <zeroOrMore>
      <element name="black" />
      <element name="white" />
   </zeroOrMore>
   <optional>
      <element name="black" />
   </optional>
</element>

XML Schema forces deterministic model groups, so you can't use that.

Cheers,

Jeni

---
Jeni Tennison
http://www.jenitennison.com/