Fwd: FW: Problem with MathML3 schema

Hi,

Tom Magliery at JustSystems seems to have spotted an issue in the MathML 3
Schema. I believe he's correct but wouldn't claim to be an XML Schema
expert. What say you?

Thanks,
Autumn

*From:* Tom Magliery [mailto:tom.magliery@justsystems.com]
*Sent:* Friday, December 05, 2014 4:16 PM
*To:* Autumn Cuellar
*Subject:* Problem with MathML3 schema



Hi Autumn,



 We think there's an invalid definition in the XSD for MathML 3. The issue
occurs within mathml3-strict-content.xsd.

http://www.w3.org/Math/XMLSchema/mathml3/

On line 65, they define a group, “semantics-ci” and that group includes
itself on line 72; according to our understanding of XSD this is not
allowed:



---------------------------------------------------------------------------------

http://www.w3.org/TR/xmlschema-1/#coss-modelGroup



2 Circular groups are disallowed. That is, within the {particles} of a
group there must not be at any depth a particle whose {term} is the group
itself.

---------------------------------------------------------------------------------



I guess I'll start with: are we misunderstanding something?



The XSDs are not normative for MathML, but this sure seems like an error
that someone would have discovered before. (Then again, I have been on the
DITA TC long enough to understand/believe that something like this could
happen.)



mag