[topicmapmail] Opera topic map question

[Alexander Mikhailian]

>> a supertype-subtype hierarchy under "person".
> In the Italian Opera topic map there *is* such a hierarchy. See

I guess I missed the link.

Being new to topic maps, I glanced over the detailed explanation of the
supertype-subtype and type-instance associations in TMDM without really
grasping those in depth.

Once I started browsing the actual topic maps (in XTM 1.0, of course), I
naturally assumed that the instanceOf element was there to convey the
meaning of a hierarchical relationship and that "instanceOf" is a
misnomer for "type". This is actually very easy to believe, due to the
ambiguous use of "instanceOf" in XTM 1.0 that is resolved in the XTM 2.0
by the introduction of the type element.

My confusion lasted long enough for me to assume that there was no
hierarchy for "Person" in the Italian Opera topic map because there were
no topics referring to the "Person" through the "instanceOf" shortcut
and I didn't look for superclass-subclass association.

XTM 2.0  tries to make this confusion less likely by disambiguating
between different uses of the instanceOf element in XTM 1.0. But it
leaves completely behind the scope the description of the particular
status of supertype-subtype and type-instance associations, to the point
that a reader willing to implement the XTM 2.0 format will have to read
through TMDM as well. Which some will definitely not do, rightfully
expecting the XTM 2.0 format description to be self-contained.

This is likely a newbie view of the problem already bogging the
minds of the topic maps community.

> Yes, I guess I should have a hierarchy there. I haven't done it for
> two reasons:
...skip...

This actually answers the question, my suspicion being that there are
cases where specifying hierarchies would be considered bad practice.
AFAICS from your answer, this not the case.

P.S. Is it right to assume that the supertype-subtype association in XTM
2.0 is just the rename of the superclass-subclass association in XTM
1.0?

--
Alexander Mikhailian