XMI12 — XMI: No way to specify the meta-meta-metamodel

It seems for completeness sake, a "XMI.metametametamodel" element would need to be provided to specify the name and version of the metametametamodel (M3 model) being used. This is because XMI doesn't require that the M3 model be MOF. Even if the M3 model must be MOF, then it should still be possible to address which version of MOF is assumed.

Below is an excerpt from the M0-level "Department" model from XMI 1.2, Appendix A.4. I have corrected it (by adding the required "version" attributes and the XML header) and expanded it include a reference to the metametamodel and metametametamodel (using a new "XMI.metametametamodel" element I am proposing):

<?xml version='1.0'?>
<XMI version="1.1" xmlns:Department="edu.university/Department">
<XMI.header>
<XMI.model name="Chemistry" version="1.0"/>
<XMI.metamodel name="Department" version="1.0"/>
<XMI.metametamodel name="UML" version="1.4"/>
<XMI.metametametamodel name="Model" version="1.3"/>
</XMI.header>
<XMI.content>
<Department:Department name="Chemistry">
<Department:Department.instructors>
<Department:Professor name="Dr. Smith" xmi.id="Smith"/>
<Department:Postdoc name="Dr. Jones" xmi.id="Jones"/>
<Department:Lecturer name="Dr. Visitor" xmi.id="Visitor"/>
<Department:TeachingAssistant name="Fred" xmi.id="Fred"/>
</Department:Department.instructors>
</Department:Department>
</XMI.content>
</XMI>

Basically, the new element would be defined just like

,

, and

.