W3C home > Mailing lists > Public > www-html-editor@w3.org > April to June 1998

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
  Standards Manager     Voice: +44 171 542 6722            London EC4P 4AJ
  Reuters Limited       Fax  : +44 171 542 8314            UK
----------------------------------------------------------------------------
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



------------------------------------------------------------------------
Any views expressed in this message are those of the individual  sender,
except  where  the  sender  specifically  states them to be the views of
Reuters Ltd.
Received on Thursday, 2 April 1998 14:12:53 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 27 March 2012 18:16:43 GMT