[sc34wg3] Semantics of subject, topic type, etc

Murray Altheim murray06 at altheim.com
Mon Jun 5 19:39:38 EDT 2006


Quoting Steve Pepper <pepper at ontopia.net>:

> Murray,
>
> You might like to get up to speed on the latest work in SC34 before claiming
> that Lars Marius' definitions lack a formally underpinning. You could
> usefully start with the following:

Both you and Lars Marius continue to imply that I have not
read these documents. They are on the web, I have read them,
many times. I am "up to speed". I had a question with Lars
Marius over his claim that his blog entry constitutes a
"formal semantics." To me it looks like a discussion document
in plain prose text. I'm sorry if I have not been clear. As
we all know, email communication has its limitations.

> Topic Maps Data Model (undergoing final ballot):
>   http://www.jtc1sc34.org/repository/0696.pdf

This does not itself contain a definition of any formal
semantics. It is defined in the same manner as XTM, using
prose and UML diagrams. It links to concepts defined in
the TMRM via Appendix A. Though it is possible (even given
that two-way link) that these documents are not formally
compatible, but that's a subject for a different discussion,
and not one I'm in any position to judge anyway. I have to
trust the ISO committee on this one.

> Topic Maps Reference Model (moving toward FCD):
>   http://www.jtc1sc34.org/repository/0710.pdf

This does contain a formal semantics. But we weren't
discussing the TMRM, nor is it referred to in the blog
entry. The blog entry states

    "One thing that's lacking in the current set of Topic
     Maps standards is defined identifiers for the Topic
     Maps constructs, like subject, topic, association, etc."

which threw me because there are such a set for both XTM 1.0
and for the current proposed TMRM and TMDM documents. Given
Lars Marius' intimate familiarity with these documents I could
not understand what he meant -- Table B.2 in the TMRM, for
example, doesn't that apply? It's hard for me to imagine he
forgot that that existed, either in XTM 1.0, the TMRM, or the
TMDM.

> Topic Maps Query Language (moving toward FCD):
>   http://www.jtc1sc34.org/repository/0731.pdf

This has a section named "formal semantics" that is empty.

> Topic Maps Constraint Language (moving toward FCD but still a bit patchy):
>   http://www.jtc1sc34.org/repository/0668.pdf

This does not contain a definition of any formal semantics,
nor even an empty placeholder section, at least none that I
noticed.

> The blog in question used, as Lars Marius noted, an ad-hoc solution. The
> implication, perhaps too subtle for those not involved in the on-going work,
> being that the real formal definitions would use TMQL, which in turn will be
> based on the TMRM.

Yes, too subtle. I reacted to Lars Marius' message stating:

:   At the Seoul meeting yesterday I presented a formal definition
:   of the semantics of key terms in TMDM. For those who want to
:   see it, go to:
:
:   http://www.garshol.priv.no/blog/40.html

as I did not see then (nor do I now) that what he had posted
constituted a "formal semantics" under any known definition
of that term, nor did it seem to refer to any document that
had. I don't see either in his blog entry nor in your
implication how one might jump from the blog entry to either
TMQL (which doesn't contain a formal semantics) or to the
TMRM (except by some unmentioned link to it in a nonexistent
bibliography).

And even if he had mentioned the TMRM, merely referring to a formally-
defined document as a bibliographic reference doesn't define anything
in the referring document formally, it just provides a grounding
reference to terms that were previously defined; it doesn't do anything
to formally define new terms unless there is a formal definition for
them. I don't see any formal definitions in any documents except in the
TMRM.

> As you will see, the world has moved on since 2001. So, please, let's spend
> our energy constructively. This forum is for people who wish to participate
> in the work of WG3, not quarrel about the interpretation of the past.

I don't see that this has much to do at all with any interpretation
of the past. The subject of the thread is whether the semantics of
subject, topic type, etc. are defined formally or not, and if so,
where. They are defined formally in the TMRM in Table B.2 and the
link from the TMDM to the TMRM is in its Appendix A. This much is
clear. I just don't see how Lars Marius blog entry fits into the
picture. I'm not looking to quarrel or waste your time but to
understand what's going on, as I don't have the luxury of being at
the WG3 meetings myself.

Murray

...........................................................................
Murray Altheim <murray06 at altheim.com>                              ===  = =
http://www.altheim.com/murray/                                     = =  ===
SGML Grease Monkey, Banjo Player, Wantanabe Zen Monk               = =  = =

       In the evening
       The rice leaves in the garden
       Rustle in the autumn wind
       That blows through my reed hut.  -- Minamoto no Tsunenobu


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