Re: meta-specs (was RE: A few things I noticed about w3c's xml-schema)

[Joel Rees <rees@server.mediafusion.co.jp>]

Jonathan Borden wrote:

> Joel Rees wrote:
>
> > Iwaku Jonathan Borden:
> >
> >
> > > As you stick each of your documents into the boxes you find that for
two
> > of
> > > the boxes, half the documents cause the box to light up and for the
> other
> > > two boxes the other half of the documents cause the box to light up.
You
> > now
> > > have your two groups of documents, and two groups of schemata. We say
> each
> > > of the schema in the group is "equal" because they each have the same
> set
> > of
> > > instance documents.
> >
> > Is this ability to compare instances assumed to be hypothetical, or can
it
> > actually be implemented for some subset of instances?
> >
>
> It can be easily implemented for some subset of documents. An instance
> validator for a schema language indicates whether a document is "valid"
with
> respect to a schema. For a DTD, this is implemented by a validating
parser.
>
> -Jonathan

Is this the right interpretation? You have two schemata, written to
different standards. You have a set of documents. Your equality comparison
is to say the two schemata are equal, for the given set of documents, iff
each schema validates each document in the set with the same result as the
other schema. And you are not talking about being able to determine
equivalence over an arbitrary set of input documents?

Joel