From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,59dddae4a1f01e1a X-Google-Attributes: gid103376,public From: bobduff@world.std.com (Robert A Duff) Subject: Re: Need help with PowerPC/Ada and realtime tasking Date: 1996/05/29 Message-ID: #1/1 X-Deja-AN: 157405847 references: <63085717wnr@diphi.demon.co.uk> <31AC0712.29DF@lmtas.lmco.com> organization: The World Public Access UNIX, Brookline, MA newsgroups: comp.lang.ada Date: 1996-05-29T00:00:00+00:00 List-Id: In article <31AC0712.29DF@lmtas.lmco.com>, Ken Garlington wrote: >...At least >in my environment, the software engineer provides feedback to the domain >engineer, so I suppose it is a software engineering job to get requirements >changed, suggest additional safety features, etc. A very good point. If a brick-layer notices that laying bricks the way the architect said is impossible or stupid or even just questionable, then the brick-layer ought to notify the architect that something is, perhaps, screwed up. >It sounds like the point has already been made, but it is also good to >remmeber that, technically, correctness and safety don't have to be related. >You can have correct software that is unsafe, and incorrect software that >is safe. I suppose it depends on your definition of "correct". The proof-of-correctness folks define "correct" to mean "correctly obeys the formal specification". To me, that's a bogus definition. In plain English, a "correct" program is one that does what it's supposed to do, regardless of whether the specification is wrong. If you show me a word processor that deletes my file when I told it to italicize a word, to me, that's incorrect, even if you can show me a (bogus) formal spec that says that the "italicize word" function should delete files. If you show me a flight-control program that crashes airplanes, that's incorrect IMHO, despite the fact that you might show me a formal spec saying it did what the formal spec says. - Bob