RE: Status of UML 2.0



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From: Bauer, Robert (rbauer@rational.com)
Date: Thu 24 Oct 2002 - 17:26:20 BST


Heinrich,

Although I don't read German well, I was able to look at the web pages you
referenced below.  One thing bothers me.  As I looked at the www.2uworks.org
website I noticed the goal of being "unambiguous" uml.  This does not seem
to be possible unless uml was no more expressive than a finite automata -
that is, one could represent uml using regular expression (or equivalently a
left/right linear grammar).  Now, I haven't thought about this very long or
deeply, but it seems to me that while it is relatively easy to check whether
two uml "graphs" are equivalent at the syntactical level, is intractable at
best and quite possibly impossible - if we were to use 1st order logic to
express the semantics, well at best it is only semi-deciable whether two 1st
order expressions are equivalent.  Since, ocl cannot yet express all of the
meta-model, it cannot possibly express the semantics of every uml model, so
while one may be able to decide whether two ocl expression are equivalent
(though I suspect even though ocl is not a 1st order logic, it is still
undecidable due to the presence of "allInstances"), the "rest" of the
semantics of the uml model are either in a natural language (clearly
impossible to determine in general whether two sentences are equivalent or
equivalently whether a sentence is ambiguous) or anything more expressive
than a F.A. (also except for discrete context free languages, clearly
impossible to determine equivalence, ambiguity, etc.).

So, for those reasons, I am not sure why the goal is stated as it is.

robert 

-----Original Message-----
From: Heinrich Hussmann [mailto:Heinrich.Hussmann@inf.tu-dresden.de]
Sent: Thursday, October 24, 2002 8:14 AM
To: puml-list@cs.york.ac.uk
Subject: Re: Status of UML 2.0


Hallo Hubert

Schau Dir mal folgende Seiten an:
www.u2-partners.org 
www.2uworks.org 

Steve Cook hat auf der UML 2002 eine private Schaetzung gesagt (nicht
oeffentlich), wann er erwartet, dass UML 2.0 ein Standard wird: Mitte
2004 fruehestens.

Viele Gruesse
Heinrich

Hubert Baumeister wrote:
> 
> Hi,
> 
> could someone please summarize the status of UML 2.0? Are there still
different proposal from
> several partners or is there by now a common proposal? How far is UML 2.0
from being a standard?
> 
> I find it a very bad decision that the UML 2.0 RFP pages on the OMG
web-site
> (http://www.omg.org/uml/) are restricted to OMG members only. These pages,
if I remember correctly,
> contained the most recent submissions to the RFPs and allowed to judge the
status of the OMG process.
> 
> Greetings,
>         Hubert
> 
> --
> Dr. Hubert Baumeister, Institut für Informatik, Universität München
> mailto:baumeist@informatik.uni-muenchen.de
> http://www.informatik.uni-muenchen.de/~baumeist
> phone (x49-89)2180-9375  * fax -9175
> 
> To remove yourself from this list please mail
puml-list-request@cs.york.ac.uk
> with a message containing the word "unsubscribe".

--
Prof. Dr. Heinrich Hussmann

Dresden University of Technology
Department of Computer Science

Phone +49 351 463 38464   (until end of February 2003)
Fax +49 351 463 38459     (until end of February 2003)
Email Heinrich.Hussmann@inf.tu-dresden.de
or    Heinrich.Hussmann@informatik.uni-muenchen.de

Please note: I will move to University of Munich by March 1, 2003.



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