From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Jean Louis Newsgroups: gmane.emacs.help Subject: Re: [External] : Re: How to make M-x TAB not work on (interactive) declaration? Date: Mon, 16 Jan 2023 13:16:51 +0300 Message-ID: References: <61c2cc81db661e2624771a06a1274eac.support1@rcdrun.com> <87y1qdct5m.fsf@gnu.org> <874jt0imh0.fsf@dataswamp.org> 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="14822"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mutt/2.2.9+54 (af2080d) (2022-11-21) Cc: Rudolf =?utf-8?Q?Adamkovi=C4=8D?= , help-gnu-emacs@gnu.org To: Yuri Khan Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Mon Jan 16 11:17:48 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 1pHMYl-0003bR-T2 for geh-help-gnu-emacs@m.gmane-mx.org; Mon, 16 Jan 2023 11:17:47 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pHMYJ-0001Rc-CR; Mon, 16 Jan 2023 05:17:19 -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 1pHMYA-0001QG-Nn for help-gnu-emacs@gnu.org; Mon, 16 Jan 2023 05:17:10 -0500 Original-Received: from stw1.rcdrun.com ([217.170.207.13]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pHMY8-0004sm-Vm for help-gnu-emacs@gnu.org; Mon, 16 Jan 2023 05:17:10 -0500 Original-Received: from localhost ([::ffff:197.239.8.177]) (AUTH: PLAIN admin, TLS: TLS1.3,256bits,ECDHE_RSA_AES_256_GCM_SHA384) by stw1.rcdrun.com with ESMTPSA id 0000000000055DC4.0000000063C52425.00006DD8; Mon, 16 Jan 2023 03:17:09 -0700 Mail-Followup-To: Yuri Khan , Rudolf =?utf-8?Q?Adamkovi=C4=8D?= , help-gnu-emacs@gnu.org Content-Disposition: inline In-Reply-To: Received-SPF: pass client-ip=217.170.207.13; envelope-from=bugs@gnu.support; helo=stw1.rcdrun.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham 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:142264 Archived-At: * Yuri Khan [2023-01-16 10:57]: > On Mon, 16 Jan 2023 at 11:44, Jean Louis wrote: > > > > >> (+) ➜ 0 > > > > > > Send me references on what is additive identity. > > > > Though that it is so, it does not answer why is it so. > > Consider a sum of n elements: S = (+ x_1 … x_{n-1} x_n). > By definition, it is equal to the sum of the first n-1 elements, plus > the nth element: S = (+ x_1 … x_{n-1}) + x_n. No problem this far? > (except for me mixing prefix and infix notation) > > Now, plug n=1 into this general formula. > S = x_1 = (+) + x_1. > Therefore, the sum of an empty list (+) has to be 0. By above I do not see reference to Lisp. What you state above is not what Lisp function is supposed to do and it does not tell why is it so in Lisp, do you know? I understand "identity element" but I do not see relation between group theory and arithmetic function in Lisp context `+': > + is a built-in function in ‘C source code’. > (+ &rest NUMBERS-OR-MARKERS) > Return sum of any number of arguments, which are numbers or markers. It does not say "Return sum of any number of arguments, which are numbers or markers, or if no arguments return identity element by using group theory, blah..." I actually expect function to tell me wrong number of arguments or no arguments, as I find it safer for programming that way. -- Jean Take action in Free Software Foundation campaigns: https://www.fsf.org/campaigns In support of Richard M. Stallman https://stallmansupport.org/