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: Software Safety (was: Need help with PowerPC/Ada and realtime tasking) Date: 1996/06/03 Message-ID: #1/1 X-Deja-AN: 158245422 references: <31AD794D.2E62@lmtas.lmco.com> organization: The World Public Access UNIX, Brookline, MA newsgroups: comp.lang.ada Date: 1996-06-03T00:00:00+00:00 List-Id: In article , Robert Dewar wrote: >What's the point of degrading this useful technical term this way. By >your definition, correct just means good or some such subjective term. >The concept of obeying a formal specification is a useful one, and it >is one which has been given the name "correctness" in the programming >language area. Well, I would prefer to call this useful concept "obeying a formal specification". At least people ought to say "correct with respect to formal spec X", rather than the shorthand "correct". I must admit that my opinion is pointless, since, as you say, the term "correct" is well established, and nobody's going to listen to just *me*. The reason I object to "correct" is that I've seen many cases where people misunderstand the term. Even people who ought to know better. I've seen arguments along these lines: "I proved so-and-so program correct. Therefore, it obviously can't have any bugs, or do anything wrong. Therefore, there's no need to test it." A bogus argument, but it's easy to fool people with that sort of argument, because "correct" really does mean "good" or "perfect" in plain English. >I admit is occasionally confusing when standard English words are (mis)used >in a specific technical way, but as long as everyone understands the >usage (and correctness has been used in this specific way for many years),m >then it is useful (after all the Ada 95 RM is full of normal English words >used in a non-standard way :-) Sure, but it's not so bad when a more-or-less neutral term is "misused" that way -- the term is just gaining a new meaning, and one can (hopefully) tell which meaning is meant from context. It's much more of a problem when the English term being hijacked has moral connotations, as does "correct". By the way, I suspect that proof techniques would be *more* popular today, if the proponents had not been overselling their case for all these years (e.g., saying that proofs avoid the need for testing, and using loaded terms like "correct" to describe what they're doing). - Bob