[Top] [All Lists]

Re: [ontac-forum] Re: The world may fundamentally be inexplicable

To: Michael Gruninger <gruninger@xxxxxxxxxxxxxxx>, ONTAC-WG General Discussion <ontac-forum@xxxxxxxxxxxxxx>, 'SUO WG' <standard-upper-ontology@xxxxxxxxxxxxxxxxx>, CG <cg@xxxxxxxxxx>
From: "John F. Sowa" <sowa@xxxxxxxxxxx>
Date: Mon, 9 Jan 2006 23:39:19 EST
Message-id: <43c33a77.14290.0@xxxxxxxxxxx>
Michael,    (01)

There is an enormous amount of both high-powered research *and*
mission critical applications of pi calculus.    (02)

> It's a mistake to make claims without backing them up with
> actual axioms.    (03)

If you want to look at axioms for pi calculus, the following
line to Google will get you 16,000 hits, some of which are
very high-powered and elegant:    (04)

   "pi calculus" axioms    (05)

If you want an ISO standard based on pi calculus, see    (06)

   ISO/IEC DIS 15437 E-LOTOS    (07)

LOTOS is widely used in the aerospace industry, and NASA uses
it for the complex and delicate timing problems in rendevous of
spacecraft with satelites and moons of Jupiter, Saturn, etc.    (08)

For the telephone networks, see the Erlang language, which is
an implementation of pi calculus used by the entire telephone
industry.  (Robin Milner, who introduced the pi calculus, was
a consultant to both ATT and British Telephone.)    (09)

And for applications closer to mainstream ontology projects,
the pi calculus is heavily used as a foundation for the
business process modeling and service oriented archictectures.
I highly recommend the following book, which has a good intro
to pi calculus for working programmers:    (010)

   _Essential Business Process Modeling_ by Michael Havey    (011)

See the O'Reilly web site for the table of contents, etc:    (012)

   http://press.oreilly.com/pub/pr/1419    (013)

I would be quite happy to have PSL and situation calculus
available in the ontology as an optional module.  But I would
also insist that pi calculus be given equal time.    (014)

> It is also misleading to say that situation calculus is used
> to reason about time.  A time ontology is used to reason
> about time; the situation calculus is used to reason about
> activities, their preconditions and effects.    (015)

Time and processes are inseparable:  Without time, you cannot
have processes; and without processes, the concept of time is
meaningless.  It's pointless to axiomatize one without the other.    (016)

The point I was trying to make is there is *no* uniquely best
axiomatization for all reasoning about time and processes.
Therefore, I strongly recommend that the upper-level ontology
be sparsely axiomatized, and the details of the axioms to be
used for any particular problem be included in a collection
of optional modules.    (017)

Bottom line:  PSL should be in one or more optional modules.
Versions based on pi calculus should be in one or more optinonal
modules.  But *neither* of them should be required.    (018)

John    (019)

Message Archives: http://colab.cim3.net/forum/ontac-forum/
To Post: mailto:ontac-forum@xxxxxxxxxxxxxx
Shared Files: http://colab.cim3.net/file/work/SICoP/ontac/
Community Wiki: 
http://colab.cim3.net/cgi-bin/wiki.pl?SICoP/OntologyTaxonomyCoordinatingWG    (020)
<Prev in Thread] Current Thread [Next in Thread>