Re: daml+oil+concrete includes XML Schema syntax? [was: ... nextsteps?]

From: Dan Connolly (
Date: 02/01/01

"Peter F. Patel-Schneider" wrote:
> I would turn things around and ask why there would be any reason to not use
> XML Schema datatypes directly.

I presume you mean "... any reason not to use the *concrete
syntax* from the XML schema datatypes spec directly"?
I do expect to use the types; just not the surface syntax.

In answer to your question...

Well... I know how to treat RDF syntax as logical formulas;
e.g. I've automated translation to KIF in the general case.
Combine that with some axioms, and you've got a complete
theory for whatever you want to talkd about. (yes,
there are details about whether classes and bags can contain
themselves or not that haven't been worked out; but
daml+oil+concrete doesn't address those either.)

I sort of know how to treat XML Schema concrete syntax
as logical formulas; we could rigorously specify
it in our spec. I think the easiest way to do that
is to specify a translation to RDF syntax.

In any case, we can't just put a one-liner
in our spec that says "and you can use XML schema
concrete syntax in there; the meaning is obvious."
At least: I would find that very unsatisfactory.
And RDF parsing software would burp. We can
show what they should do in stead of burping,
but that's a non-trivial amount of work.

> Using XML Schema datatypes directly instead of translating them is much
> better in terms of reuse and extension.

Er... really? I don't think so; but I would have to see
a specification of how to use them "directly" first.
I don't see one in

e.g. what semantics is assigned to declarations like this one?

<xsd:simpleType name="over12">
  <!-- over12 is an XMLS datatype based on positiveIntege -->
  <!-- with the added restriction that values must be >= 13 -->
  <xsd:restriction base="xsd:positiveInteger">
  <xsd:minInclusive value="13"/>

I don't see anything relevant in

>  If reuse and extension is not one
> of our goals, then I have lots of suggestions on how to change the syntax
> of DAML+OIL for the better.
> Translating XML Schema datatype constructors requires work.

Using them "directly" requires work too.

> Adding XML Schema datatype-derived constructors to DAML+OIL (abstract)
> classes requires a rethink of the semantics.

How so?

> peter
> From: Dan Connolly <>
> Subject: daml+oil+concrete includes XML Schema syntax? [was: ... next steps?]
> Date: Thu, 01 Feb 2001 12:03:39 -0600
> > Are you proposing to extend DAML+OIL syntax to include
> > XML Schema syntax? I don't see any reason to do that.
> > We can express things like minInclusive in the
> > same style that we express domain, range, cardinality,
> > etc., no?

Dan Connolly, W3C
office: tel:+1-913-491-0501
  (put return phone number in from/subject)

This archive was generated by hypermail 2.1.4 : 04/02/02 EST