From: kahn@ambra.drcoffsite.com (Larry Kahn)
Subject: Re: Problems with proofs
Date: 1995/04/21
Date: 1995-04-21T00:00:00+00:00 [thread overview]
Message-ID: <4157cb$f21a.59@ambra.drcoffsite.com> (raw)
In-Reply-To: cppD7BMEw.2ts@netcom.com
In article <cppD7BMEw.2ts@netcom.com>, cpp@netcom.com says...
>
><< [Proofs take into account hardware failure] if the spec includes
>this, and they don't if the spec does not. >>
>
>Isn't this a pretty loose way to look at proof? Proving that you
>conformed to a (possibly erroneous) specification sounds a lot less
>impressive than saying you have a "proof of correctness."
>
><< I think you have an idea that a program that is proved correct
>is guaranteed to work. >>
>
hate to jump into this but I agree a proof of correctness is a formal method of proving that the program does what you
expect it to do (WITH RESPECT TO A CERTAIN SPECIFICATION)!!!!
this is the key... it is only correct with respect to the spec. and if your spec is in error of course the program will not
perform correctly.
The bottom line is that correctness is a relative term .. I may thing a program should print out a certain error message
when certain conditions occur and this was not in the original spec and therefore the developers did not implement it.
In terms of the developers the program may still be correct and even verifiable proved as correct with response to a certain
spec ... but in my eyes I may say it is incorrect.. this the relativity of correctness (ie relative to individial opinion)
But proof of correctness is a formal methodology for proving the program corresponds to what you expect it to do in relation
to a specification and this is a different issue than whether or not I believe the program is correct in my eyes...
You need to get a book on proof of correctness and look at the definitions more carefully proof of correctness does
not proof that the program handles all possible values, never crashes, halts, etc..... I think this is what you are
confusing with the term "correctness".....
--
Laurence G. Kahn
Senior Software Engineer
Dynamics Research Corp.
(Finger .site@ambra.drcoffsite.com for PGP public key.)
(Internet Phone address: LGK in private forum drcoffsite)
next prev parent reply other threads:[~1995-04-21 0:00 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
1995-03-17 0:24 Should internet support software be written in Ada? Bill Brooks
1995-03-17 8:47 ` Anthony Shipman
1995-03-19 22:06 ` David Weller
1995-03-23 15:05 ` Theodore Dennison
1995-03-24 10:26 ` Fred J. McCall
1995-03-27 9:50 ` Robb Nebbe
1995-03-27 19:43 ` State machines and Goto's (was Re: Should internet support software be written in Ada?) Robert I. Eachus
1995-03-27 23:14 ` Arthur Evans Jr
1995-03-29 0:00 ` Dan
1995-04-01 0:00 ` Mike White
1995-04-04 0:00 ` Robert Dewar
1995-04-06 0:00 ` Theodore Dennison
1995-04-06 0:00 ` Norman H. Cohen
1995-04-07 0:00 ` Robert Dewar
1995-04-07 0:00 ` Tucker Taft
1995-04-07 0:00 ` Mike White
[not found] ` <3ma7rt$smt@kaiwan009.kaiwan.com>
[not found] ` <dewar.797514490@gnat>
[not found] ` <3meunj$66u@felix.seas.gwu.edu>
1995-04-20 0:00 ` CS teachers who can't code their way outta a paper bag Richard A. O'Keefe
1995-03-27 14:24 ` Should internet support software be written in Ada? Theodore Dennison
1995-03-28 0:00 ` Robert Dewar
1995-03-28 9:32 ` Fred J. McCall
1995-03-29 0:00 ` Theodore Dennison
1995-03-29 0:00 ` Robert I. Eachus
1995-03-31 0:00 ` Theodore Dennison
1995-04-05 0:00 ` Wes Groleau
1995-04-07 0:00 ` State machines and Goto's (was Re: Should internet support software be written in Ada?) Wes Groleau
1995-04-07 0:00 ` Robert Firth
[not found] ` <D6qyv0.6Jv@nntpa.cb.att.com>
1995-04-19 0:00 ` Fergus Henderson
1995-04-19 0:00 ` Fred J. McCall
1995-04-19 0:00 ` George Haddad
1995-04-20 0:00 ` Mark A Biggar
1995-04-20 0:00 ` State machines and Goto's (was Re: Sho Brian Hanson
1995-04-20 0:00 ` State machines and Goto's (was Re: Should internet support software be written in Ada?) Bill Winn
1995-04-20 0:00 ` Robert Dewar
1995-03-22 23:08 ` Should internet support software be written in Ada? Keith Thompson
[not found] ` <3mrv7h$3mq@larry.rice.edu>
[not found] ` <3msnu4$6am@kaiwan009.kaiwan.com>
[not found] ` <KUBEK.95Apr18213646@insage.gerii.insa-tlse.fr>
[not found] ` <cppD792GC.1uI@netcom.com>
1995-04-20 0:00 ` Teaching OO/C++ Philip Machanick
[not found] ` <3me1qs$n4a@theopolis.orl.mmc.com>
[not found] ` <3mevmu$8an@felix.seas.gwu.edu>
[not found] ` <3mh75i$8eu@rational.rational.com>
[not found] ` <3mjihr$iqq@felix.seas.gwu.edu>
[not found] ` <3mp20f$80t@kaiwan009.kaiwan.com>
1995-04-20 0:00 ` Academic CS Losers? Phillip Fanous
1995-04-21 0:00 ` Bill Winn
[not found] ` <dewar.798207931@gnat>
[not found] ` <cppD78ywq.B31@netcom.com>
[not found] ` <dewar.798240702@gnat>
1995-04-19 0:00 ` Problems with proofs Brian Harvey
1995-04-19 0:00 ` Robert Dewar
1995-04-20 0:00 ` Robin Rowe
1995-04-20 0:00 ` Steve Tate
1995-04-20 0:00 ` Apology to Steve Robin Rowe
1995-04-20 0:00 ` Problems with proofs Robert Dewar
1995-04-20 0:00 ` Robert Dewar
1995-04-21 0:00 ` Robin Rowe
1995-04-21 0:00 ` Robert Dewar
1995-04-21 0:00 ` Larry Kahn [this message]
1995-04-20 0:00 ` Robin Rowe
[not found] ` <3n1fsv$lgd@butch.lmsc.lockheed.com>
1995-04-20 0:00 ` Robin Rowe
1995-04-20 0:00 ` Garlington KE
[not found] ` <dewar.798093453@gnat>
1995-04-20 0:00 ` What good is halting prob? Max Hailperin
[not found] ` <cppD75t6F.47M@netcom.com>
[not found] ` <EACHUS.95Apr17172831@spectre.mitre.org>
[not found] ` <cppD77Ex6.E77@netcom.com>
[not found] ` <3mve9b$gaj@news.cais.com>
1995-04-18 0:00 ` Jay M Martin
1995-04-19 0:00 ` Steve Tate
1995-04-20 0:00 ` Jay M Martin
1995-04-21 0:00 ` Steve Tate
1995-04-21 0:00 ` Ray Toal
[not found] ` <cppD7880n.32B@netcom.com>
1995-04-19 0:00 ` Randolph Crawford
1995-04-19 0:00 ` Robert Dewar
1995-04-20 0:00 ` Robin Rowe
1995-04-20 0:00 ` Robert Dewar
1995-04-20 0:00 ` Robin Rowe
1995-04-21 0:00 ` Brian Hanson
1995-04-21 0:00 ` sxc
[not found] ` <dewar.798172270@gnat>
[not found] ` <cppD786FM.1u9@netcom.com>
1995-04-19 0:00 ` Mark A Biggar
1995-04-19 0:00 ` Richard Ladd Kirkham
1995-04-19 0:00 ` Robert Dewar
1995-04-20 0:00 ` Richard Ladd Kirkham
1995-04-20 0:00 ` Robert Dewar
1995-04-21 0:00 ` Mark A Biggar
[not found] ` <dewar.798207364@gnat>
[not found] ` <3n0ka7$b57@hermes.unt.edu>
[not found] ` <dewar.798232482@gnat>
1995-04-19 0:00 ` Mark A Biggar
1995-04-19 0:00 ` Robert Dewar
1995-04-19 0:00 ` Steve Tate
[not found] ` <cppD78xMv.49w@netcom.com>
1995-04-19 0:00 ` Robb Nebbe
1995-04-21 0:00 ` Robert I. Eachus
1995-04-21 0:00 ` Robert Dewar
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