XMI12 — Composition Association problems

According to the DTD generation EBNF, a Class element contains embedded
<class-name> elements for Classes (and their subclasses) related as
components via composite Associations. According to the DTD generation
pseudo-code, the embedded elements are <reference-name> elements.
Neither of these approaches work properly: both fail for some valid and
meaningful meta-models.

Discussion:

The first approach can fail when there is more than one composite Association
in the meta-model. For example:

package P {
class C1

;

association A1

;
};

The resulting DTD for this meta-model does not allow you to tell if a
a C1 instance that is related to a (component) C2 instance via an A1
link or an A2 link.

The second approach fails if there is no reference to the component
Class from the composite Class. For example

package P {
class C1

;

class C2

;

association A1

;
};

Since there is no Reference from C1 to C2, there is no name for the
element.