From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Nick Dokos Newsgroups: gmane.emacs.help Subject: Re: [External] : Re: How to make M-x TAB not work on (interactive) declaration? Date: Tue, 17 Jan 2023 11:25:33 -0500 Message-ID: <87edrtqgaq.fsf@alphaville.usersys.redhat.com> 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="22402"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:w+QuD93GSIUuxzNX71rgYyo1e5Q= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Tue Jan 17 17:26:08 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 1pHoml-0005aG-VS for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 17 Jan 2023 17:26:07 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pHoma-0001qy-21; Tue, 17 Jan 2023 11:25:56 -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 1pHomO-0001lr-CW for help-gnu-emacs@gnu.org; Tue, 17 Jan 2023 11:25:44 -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 1pHomM-0005pg-Fy for help-gnu-emacs@gnu.org; Tue, 17 Jan 2023 11:25:43 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1pHomK-0004xa-6U for help-gnu-emacs@gnu.org; Tue, 17 Jan 2023 17:25:40 +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: 5 X-Spam_score: 0.5 X-Spam_bar: / X-Spam_report: (0.5 / 5.0 requ) BAYES_00=-1.9, DKIM_ADSP_CUSTOM_MED=0.001, FORGED_GMAIL_RCVD=1, FREEMAIL_FORGED_FROMDOMAIN=0.249, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.25, NML_ADSP_CUSTOM_MED=0.9, 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:142315 Archived-At: writes: > On Mon, Jan 16, 2023 at 12:08:33AM +0300, Jean Louis wrote: >> * Rudolf Adamkovič [2023-01-15 23:27]: >> > Jean Louis writes: >> > >> > >> (+) ➜ 0 >> > > >> > > Why? It is wrong. >> > >> > In Lisp, the `+' operator returns the sum of the additive identity with all of >> > its arguments. The additive identity equals zero and you provided zero >> > arguments. Hence, you get the additive identity. >> >> Send me references on what is additive identity. > > Identity element [0] as defined in group theory [1]. > > The association of 0 with + and 1 with * runs deeper in maths > than you think. > >> Though that it is so, it does not answer why is it so. > > Those are, of course, conventions. As whether the natural > numbers begin with 0 or 1. But the above is, AFAIK, most > widespread among mathematicians, wheter the latter is not. > > Cheers > > [0] https://en.wikipedia.org/wiki/Identity_element > [1] https://en.wikipedia.org/wiki/Group_theory The "empty sum" and "empty product" conventions are described in the corresponding articles in Wikipedia too - they might help: https://en.wikipedia.org/wiki/Empty_sum https://en.wikipedia.org/wiki/Empty_product -- Nick