From: Phil Clayton <phil.clayton@lineone.net>
Subject: Re: Convention for naming of anything
Date: Sun, 19 Feb 2012 10:07:15 -0800 (PST)
Date: 2012-02-19T10:07:15-08:00 [thread overview]
Message-ID: <6eb22e0f-bb55-4d03-8b63-f6a6c248e295@m24g2000yqb.googlegroups.com> (raw)
In-Reply-To: op.v9r8wwueule2fv@douda-yannick
On Feb 16, 5:44 pm, Yannick Duchêne (Hibou57)
<yannick_duch...@yahoo.fr> wrote:
> With functional representation in mind, when an object X' is a value
> derived from an object X in a recursive algorithm, which way do you name
> both X and X', as the Prime symbol is not allowed in Ada names?
To refer to before and after values of a variable in e.g. a
postcondition, the convention of suffixing a subscript-zero to denote
the before value is fairly common in formal methods texts, e.g. the
classic "Programming from Specifications":
http://www.cs.ox.ac.uk/publications/books/PfS/
So, for example, the postcondition
X = X₀ + 1
says that the value of X is increased by 1. Perhaps an ASCII
equivalent would be
X = X_0 + 1
I've come across exactly this conflict with primes in the past. The
Ada verification tool, DAZ - built on ProofPower, see
http://www.lemma-one.com/ProofPower/index/
- would have ideally used a prime to denote an after value because
that is the convention of the Z notation, the language used to express
pre- and postconditions of Ada statements. Instead it uses a
subscript-zero for the before value, like in Programming from
Specifications, on which it was based.
Phil
next prev parent reply other threads:[~2012-02-19 18:14 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-09 21:10 Convention for naming of packages Yannick Duchêne (Hibou57)
2012-02-09 21:39 ` Jeffrey Carter
2012-02-10 15:07 ` Yannick Duchêne (Hibou57)
2012-02-10 17:04 ` Georg Bauhaus
2012-02-10 17:09 ` Georg Bauhaus
2012-02-10 17:41 ` Yannick Duchêne (Hibou57)
2012-02-13 9:33 ` Yannick Duchêne (Hibou57)
2012-02-11 0:56 ` Randy Brukardt
2012-02-13 3:09 ` BrianG
2012-02-10 17:21 ` Pascal Obry
2012-02-10 18:03 ` Yannick Duchêne (Hibou57)
2012-02-11 1:06 ` Randy Brukardt
2012-02-11 9:22 ` Simon Wright
2012-02-11 10:17 ` Yannick Duchêne (Hibou57)
2012-02-11 19:24 ` Yannick Duchêne (Hibou57)
2012-02-11 20:06 ` Simon Wright
2012-02-12 9:18 ` Yannick Duchêne (Hibou57)
2012-02-12 10:22 ` Simon Wright
2012-02-13 9:21 ` Yannick Duchêne (Hibou57)
2012-02-12 19:53 ` J-P. Rosen
2012-02-12 21:19 ` Yannick Duchêne (Hibou57)
2012-02-13 8:53 ` Dmitry A. Kazakov
2012-02-13 9:12 ` Yannick Duchêne (Hibou57)
2012-02-13 11:03 ` Dmitry A. Kazakov
2012-02-13 11:57 ` Yannick Duchêne (Hibou57)
2012-02-13 12:30 ` Yannick Duchêne (Hibou57)
2012-02-13 13:07 ` Dmitry A. Kazakov
2012-02-13 14:01 ` Yannick Duchêne (Hibou57)
2012-02-13 14:59 ` Dmitry A. Kazakov
2012-02-13 15:05 ` Yannick Duchêne (Hibou57)
2012-02-13 15:23 ` Dmitry A. Kazakov
2012-02-14 21:02 ` Yannick Duchêne (Hibou57)
2012-02-13 13:01 ` Dmitry A. Kazakov
2012-02-13 13:04 ` Yannick Duchêne (Hibou57)
2012-02-13 13:19 ` Dmitry A. Kazakov
2012-02-13 14:20 ` Yannick Duchêne (Hibou57)
2012-02-13 15:11 ` Dmitry A. Kazakov
2012-02-13 16:24 ` Yannick Duchêne (Hibou57)
2012-02-13 17:19 ` Dmitry A. Kazakov
2012-02-13 18:10 ` Yannick Duchêne (Hibou57)
2012-02-13 21:02 ` Dmitry A. Kazakov
2012-02-14 9:08 ` Yannick Duchêne (Hibou57)
2012-02-14 13:33 ` Dmitry A. Kazakov
2012-02-14 14:40 ` Yannick Duchêne (Hibou57)
2012-02-14 15:26 ` Dmitry A. Kazakov
2012-02-13 10:45 ` Georg Bauhaus
2012-02-13 10:59 ` Yannick Duchêne (Hibou57)
2012-02-14 10:18 ` Yannick Duchêne (Hibou57)
2012-02-14 11:51 ` Yannick Duchêne (Hibou57)
2012-02-14 22:21 ` Manuel Collado
2012-02-15 4:09 ` Simon Wright
2012-02-15 6:13 ` Niklas Holsti
2012-02-15 11:26 ` Yannick Duchêne (Hibou57)
2012-02-15 11:39 ` Georg Bauhaus
2012-02-15 11:47 ` Georg Bauhaus
2012-02-15 6:30 ` J-P. Rosen
2012-02-15 8:36 ` Simon Wright
2012-02-15 22:56 ` Robert A Duff
2012-02-15 11:27 ` Yannick Duchêne (Hibou57)
2012-02-15 11:43 ` Georg Bauhaus
2012-02-15 12:33 ` Georg Bauhaus
2012-02-15 12:55 ` Yannick Duchêne (Hibou57)
2012-02-15 17:30 ` Georg Bauhaus
2012-02-09 22:33 ` Simon Wright
2012-02-09 22:35 ` J-P. Rosen
2012-02-10 14:38 ` Yannick Duchêne (Hibou57)
2012-02-10 9:47 ` Mart van de Wege
2012-02-10 14:24 ` Yannick Duchêne (Hibou57)
2012-02-13 3:02 ` BrianG
2012-02-10 12:19 ` Brian Drummond
2012-02-10 14:22 ` Yannick Duchêne (Hibou57)
2012-02-10 19:16 ` Jeffrey Carter
2012-02-11 16:31 ` Martin Dowie
2012-02-16 17:44 ` Convention for naming of anything Yannick Duchêne (Hibou57)
2012-02-17 19:46 ` Yannick Duchêne (Hibou57)
2012-02-17 21:53 ` Manuel Collado
2012-02-17 22:12 ` Yannick Duchêne (Hibou57)
2012-02-17 23:52 ` Adam Beneschan
2012-02-18 0:24 ` Yannick Duchêne (Hibou57)
2012-02-18 0:50 ` Yannick Duchêne (Hibou57)
2012-02-18 22:53 ` BrianG
2012-02-19 11:16 ` Simon Wright
2012-03-06 0:36 ` Randy Brukardt
2012-02-18 11:32 ` Georg Bauhaus
2012-02-18 13:02 ` Yannick Duchêne (Hibou57)
2012-02-19 18:07 ` Phil Clayton [this message]
2012-02-19 21:53 ` Yannick Duchêne (Hibou57)
2012-02-20 0:21 ` Phil Clayton
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