Re: [moca] Paper: The Kell Calculus: A Family of Higher-Order Distributed Process Calculi

[Michael Baldamus <michaelb@xxxxxxxx>]

On Fri, 8 Oct 2004, Thomas Hildebrandt wrote:

> Hi Alan,
>
> thank you for your reply, the typo does explain some of my confusion,
> but I am still a bit puzzled
> exactly which definitions that contain typos, maybe you can clarify
> that for me.
> >
>
> > Surprisingly enough, we did not know Howe's method when we started
> > working on bisimulations for the Kell Calculus. As generalizing it to
> > nested locations seemed as hard as the approach we were using, we did
> > not pursue it.
> >
>
> I can recommend the presentation of Baldamus and Frauenstein. It can be
> found online in a technical report 95-21 from Berlin University of
> Technology, 1995.

If I may add something to that, I would say that the method is
presented in an even more systematic way in my thesis, which can
be downloaded via http://user.it.uu.se/~michaelb/papers. The
advantage of this presentation is that it does completely away
with the pervasive use of structural congruence that we still
thought to be necessary when we wrote the technical report. I
treated only the case of late context bisimulation for pure
second-order processes, though. I do not know if the approach
from my thesis would work for other calculi and/or other forms of
bisimulation.

> (We are right now working on an extension of the method to early
> bisimulations, which would
> provide a sound and complete characterisation of the barbed congruence
> for Homer.)

That's interesting. Thomas claimed to have achieved a similar
extension in *his* thesis, which is however written in German. I
have to tell that I never read this proof, so I can not really
tell anything more definite about it. Maybe he will give some
information about it if he reads this message here.

Best regards

  Michael

+ Michael Baldamus (postdoctoral researcher) - Uppsala University,
| Department of Information Technology, Box 337, 751 05 UPPSALA,
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