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Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade!

Newsgroups comp.lang.lisp, comp.emacs, comp.lang.python, comp.lang.perl.misc
From Albert van der Horst <albert@spenarnc.xs4all.nl>
Subject Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade!
Date 2012-03-12 19:00 +0000
Followup-To comp.lang.python
Message-ID <m0scsu.8xu@spenarnc.xs4all.nl> (permalink)
Organization Dutch Forth Workshop
References <0078bbfb-5dfc-48fc-af1a-69de3cf15c3e@b1g2000yqb.googlegroups.com> <m0rrtp.2pl@spenarnc.xs4all.nl> <4f5df4b3$0$1375$4fafbaef@reader1.news.tin.it>

Cross-posted to 4 groups.

Followups directed to: comp.lang.python

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In article <4f5df4b3$0$1375$4fafbaef@reader1.news.tin.it>,
Kiuhnm  <kiuhnm03.4t.yahoo.it> wrote:
>On 3/12/2012 12:27, Albert van der Horst wrote:
>> Interestingly in mathematics associative means that it doesn't matter
>> whether you use (a.b).c or a.(b.c).
>> Using xxx-associativity to indicate that it *does* matter is
>> a bit perverse, but the Perl people are not to blame if they use
>> a term in their usual sense.
>
>You may see it this way:
>Def1. An operator +:SxS->S is left-associative iff
>   a+b+c = (a+b)+c for all a,b,c in S.
>Def2. An operator +:SxS->S is right-associative iff
>   a+b+c = a+(b+c) for all a,b,c in S.
>Def3. An operator +:SxS->S is associative iff it is both left and
>right-associative.

I know, but what the mathematicians do make so much more sense:
(a+b)+c = a+(b+c)    definition of associative.
Henceforth we may leave out the brackets.

Don't leave out the brackets if the operators if the operators is
not associative.

P.S. There is no need for the operators to be SxS->S.
For example a b c may be m by n, n by l, l by k matrices respectively.

>
>Kiuhnm

Groetjes Albert

--
-- 
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- being exponential -- ultimately falters.
albert@spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst

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New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Xah Lee <xahlee@gmail.com> - 2012-02-29 00:09 -0800
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Chiron <chiron613@gmail.com> - 2012-02-29 11:43 +0000
    Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-02-29 07:12 -0500
    Re: New Science Discovery: Perl Detracters Remain Idiots After A Decade! Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-02-29 23:06 -0500
      Re: New Science Discovery: Perl Detracters Remain Idiots After A Decade! Chiron <chiron613@gmail.com> - 2012-03-01 04:52 +0000
        Re: New Science Discovery: Perl Detracters Remain Idiots After A Decade! Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-03-01 10:07 -0500
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-02-29 13:08 +0100
    Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Xah Lee <xahlee@gmail.com> - 2012-02-29 16:02 -0800
      Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-01 12:00 +0100
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Xah Lee <xahlee@gmail.com> - 2012-03-02 05:12 -0800
          Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-02 15:15 +0100
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Rainer Weikusat <rweikusat@mssgmbh.com> - 2012-02-29 15:15 +0000
    Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-02-29 17:18 +0100
    Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-02-29 23:10 -0500
      Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Chiron <chiron613@gmail.com> - 2012-03-01 05:07 +0000
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-03-01 10:13 -0500
          Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Chiron <chiron613@gmail.com> - 2012-03-02 14:17 +0000
            Re: New Science Discovery: Perl Detractors Remain Idiots After A Decade! Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-03-02 10:53 -0500
              Re: New Science Discovery: Perl Detractors Remain Idiots After A Decade! Chiron <chiron613@gmail.com> - 2012-03-02 19:06 +0000
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-03-01 16:58 -0500
      Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Rainer Weikusat <rweikusat@mssgmbh.com> - 2012-03-01 14:40 +0000
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-03-01 16:11 -0500
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! namekuseijin <namekuseijin@gmail.com> - 2012-02-29 09:45 -0800
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Westley Martínez <anikom15@gmail.com> - 2012-03-01 16:46 -0800
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Chiron <chiron613@gmail.com> - 2012-03-02 07:27 +0000
  Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-03-12 11:27 +0000
    Re: New Science Discovery: Perl Detractors Remain Idiots After A Decade Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-03-12 08:40 -0400
      Re: New Science Discovery: Perl Detractors Remain Idiots After A Decade Raymond Wiker <raw@unknown-00-23-6c-8d-9e-26.lan> - 2012-03-12 19:20 +0100
    Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-12 14:05 +0100
      Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Albert van der Horst <albert@spenarnc.xs4all.nl> - 2012-03-12 19:00 +0000
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-12 21:27 +0100
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-13 12:00 +0100
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-13 12:03 +0100
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots Af Shmuel (Seymour J.) Metz <spamtrap@library.lspace.org.invalid> - 2012-03-12 16:20 -0400
        Re: New Science Discovery: Perl Idiots Remain Idiots After A Decade!New Science Discovery: Perl Idiots Remain Idiots After A Decade! Kiuhnm <kiuhnm03.4t.yahoo.it> - 2012-03-13 17:41 +0100

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