From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: =?utf-8?Q?=C3=93scar_Fuentes?= Newsgroups: gmane.emacs.help Subject: Re: (*) -> 1 Date: Wed, 18 Jan 2023 18:14:48 +0100 Message-ID: <87zgaf933r.fsf@telefonica.net> References: <87sfg9kuya.fsf@web.de> <87bkmxkpzg.fsf@web.de> <878ri1av5j.fsf@telefonica.net> <87ilh4kgqo.fsf@web.de> <87zgagakh5.fsf@telefonica.net> <87cz7cka06.fsf@web.de> <87v8l49t8w.fsf@telefonica.net> <87h6wo9fjb.fsf@telefonica.net> <87edrsufdd.fsf@web.de> <878ri09bsh.fsf@telefonica.net> <87ilh3hl36.fsf@eder.anydns.info> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="40815"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:vQwY6YdQWQX0I7CsKLAGO7hnOiw= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Wed Jan 18 18:15:33 2023 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1pIC29-000ASz-1D for geh-help-gnu-emacs@m.gmane-mx.org; Wed, 18 Jan 2023 18:15:33 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pIC1f-00067G-D2; Wed, 18 Jan 2023 12:15:03 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pIC1d-00066o-6f for help-gnu-emacs@gnu.org; Wed, 18 Jan 2023 12:15:01 -0500 Original-Received: from ciao.gmane.io ([116.202.254.214]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pIC1b-0006pU-HF for help-gnu-emacs@gnu.org; Wed, 18 Jan 2023 12:15:00 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1pIC1Y-0009XX-6w for help-gnu-emacs@gnu.org; Wed, 18 Jan 2023 18:14:56 +0100 X-Injected-Via-Gmane: http://gmane.org/ Received-SPF: pass client-ip=116.202.254.214; envelope-from=geh-help-gnu-emacs@m.gmane-mx.org; helo=ciao.gmane.io X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:142366 Archived-At: Andreas Eder writes: > On Mi 18 Jan 2023 at 15:07, Óscar Fuentes wrote: > >> Michael Heerdegen writes: >> >>> Óscar Fuentes writes: >>> >>>> Even a programmer can't assume that associativity and commutativity >>>> can be used on a long, finite, sum. >>> >>> As long as it's a sum, of course can a programmer assume that. >> >> Of course not! Otherwise your numerical simulation can go very wrong :-) >> >> (hint: numbers in computers are approximate, adding small numbers to >> large numbers is a bad idea.) > > Only floating point numbers. Which proves my point :-) And you say "only" as if floating point numbers were rarely used. > Integers are exact and in lisps like elisp > there is no artificial size limit. If your calculation consists on adding arbitrary precision integers, *that's* a rarity. If your calculation adds fixed-width integers (which includes platform integers), you definitely need to worry about order of terms.