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Re: Possible misuse of idempotent in HTML 4.0 December para 17.1

From: Misha Wolf <misha.wolf@reuters.com>
Date: Thu, 02 Apr 1998 20:11:38 +0000 (GMT)
Message-Id: <B0001558278@ritig6.rit.reuters.com>
To: www html editor <www-html-editor@w3.org>
David Woolley wrote:

> >   "relating to or being a mathematical quantity which is not zero
> >   and
> >    which when applied to itself under a given binary operation (as
> > multiplication)
> >    equals itself; also: relating to or being an operation
> >    under which a mathematical quantity is idempotent"
> I've only seen the term used in technical papers on databases.  I 
> think this has a similar meaning, but its not that clear!
> It's probably safest to avoid the term entirely.

An idempotent operation is an operation which has the property that it is 
impossible to tell (by looking at the results) whether it has been carried 
out just once or many times.

Example of an idempotent file write: Write 0x41 to the first byte of file A.

Example of an non-idempotent file write: Append 0x41 to the end of of file A.

  Misha Wolf            Email: misha.wolf@reuters.com      85 Fleet Street
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12th International Unicode Conference, 8-10 Apr 1998, Tokyo, www.unicode.org
   7th World Wide Web Conference, 14-18 Apr 1998, Brisbane, www7.conf.au

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Received on Thursday, 2 April 1998 14:12:53 UTC

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