[SystemSafety] Logic

Peter Bernard Ladkin ladkin at rvs.uni-bielefeld.de
Sat Feb 15 19:32:02 CET 2014


John,

obviously I agree with much of what you say. But I am discussing with people who believe that we
constitute an exception to much of it.

On 2014-02-15 16:02 , John Knight wrote:
> In my opinion, the situation is as follows:
> 
>   * To a very large extent, all software is critical in some way.  Even gaming software, the failure
>     of which could lead to loss of reputation, market, income, etc.

All commercial SW. But people in research areas such as AI and robotics write code all the time
which they just write. Small routines; they debug by running it; they build a cumulative collection
of more-or-less running code. That's been going on for forty years at least, probably sixty. If you
don't get the code right, then your thesis or paper is late.

The answer to the importance of SW would be "this is the kind of code we write here. Yes, other
people in industry may have to write dependable code there, but we are not pretending we teach those
techniques here, for we don't need them."

(Well, I think they do. At least some people are aware there are safety issues around mobile-robot
interactions. But I worked around that institute for four years and couldn't get anyone interested
in a safety analysis of what they were doing. They think it's stuff for lawyers and insurance
companies, not informaticians. That view will go swimmingly well until the first accident.)

>   * All of engineering rests to some extent on mathematics.

No question. But which in particular? People around here would say they don't use logic. Indeed they
don't, for two reasons: (a) they don't know any; and (b) they don't write specifications for what
they do. And they don't appear to suffer any comparative disadvantage from that. If SW doesn't work,
then it doesn't work and they fix it or write something else or just don't graduate.

>   * Discrete mathematics (the term I would use where you have used logic) is the mathematics of
>     computer engineering.

Discrete math is way more than logic, of course. It includes standard things about sets and
relations. And combinatorics. The answer is that people here don't think they use any of that, for
similar reasons as above. "We don't do computer engineering - we do applied informatics for
robotics, and biology and chemistry and physics, and artificial cognition."

>   * We will not make progress against the serious assurance challenges we face unless we apply
>     mathematics.

Yes, but dependability of SW is not thought to be an issue for our students and their research.
"They will learn that in industry when they leave, if they need to."

>   * All computer engineers should be trained to understand, appreciate and apply discrete mathematics.

Again, the response is that "we don't educate computer engineers".

There is a talk being given at the Heinz Nixdorf Institute in Paderborn next week on "Model-based
development of SW for intelligent industrial systems." Two of the CITEC people recommended it, one
of them highly. "Industrial intelligent systems" is a buzzword here, attached to a national program
based on regional industry/academic consortia of which we belong to the first. "Model-based
development" is also a newish buzzword. Of course, you can't do any "model-based" SW development
unless you use FDLs. Still, joining the dots here seems to be hard work. (The guy giving the talk is
a former student of Willi Schäfer.)

PBL

-- 
Prof. Peter Bernard Ladkin, Faculty of Technology, University of Bielefeld, 33594 Bielefeld, Germany
Tel+msg +49 (0)521 880 7319  www.rvs.uni-bielefeld.de






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