From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Yuri Khan Newsgroups: gmane.emacs.help Subject: Re: [External] : Re: How to make M-x TAB not work on (interactive) declaration? Date: Tue, 17 Jan 2023 22:59:43 +0700 Message-ID: References: <874jt0imh0.fsf@dataswamp.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="4806"; mail-complaints-to="usenet@ciao.gmane.io" To: Drew Adams , =?UTF-8?Q?Rudolf_Adamkovi=C4=8D?= , "help-gnu-emacs@gnu.org" Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Tue Jan 17 17:00:39 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 1pHoO6-00016p-Qa for geh-help-gnu-emacs@m.gmane-mx.org; Tue, 17 Jan 2023 17:00:38 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pHoNW-0001hr-JR; Tue, 17 Jan 2023 11:00:02 -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 1pHoNU-0001gz-8x for help-gnu-emacs@gnu.org; Tue, 17 Jan 2023 11:00:00 -0500 Original-Received: from mail-wm1-x336.google.com ([2a00:1450:4864:20::336]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pHoNR-0001Yr-OP for help-gnu-emacs@gnu.org; Tue, 17 Jan 2023 11:00:00 -0500 Original-Received: by mail-wm1-x336.google.com with SMTP id c4-20020a1c3504000000b003d9e2f72093so21339703wma.1 for ; Tue, 17 Jan 2023 07:59:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=zPIZQRFwXs+7pbeVNmrJMXW2evF3agMnnxXX+DaqRGo=; b=d96w4y7iaiVT/WK1aV80nm/q6hewQwQD2aUa+UCJmEZLvZh+w/3z6XMxWU33NAC35q DTxHodLDxWuPBZQwLbl0vQdp/xlwiFonpqPWQM+PjRBoRda/ggqvrlXS3PblgPdxvNQk bX2ZvK9+AYJ1R69XVjk3+pCmf0hIgq8LUIem8olFfnrvP2d+qt0JT3f6KibUscC61QDP sRk/ssVDIp22uvQfaYi5J3IVrihuO16d+p4pto+r81PVqvKJcT9G6SlP+Woms+jXDZjE XdJjzYGqToR4AG6jVox3XrewRjxsIHi7iF0hHx6TuTDJ/nl3pWg4SkREcQpJvgDwGs+F xllA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=zPIZQRFwXs+7pbeVNmrJMXW2evF3agMnnxXX+DaqRGo=; b=neukvoUwyNYMPhgFnNcQbUbM5q+qn1iaLzbJrxHEATub2HaNChi58e2tyDwksNcIZq Z0zUsG3AtOlzqBsVHJQTeC0QFaAUTJ8wfKilBOjm39I8fwAj6zsbJ3jh6ckLibPaB5jm 5WYmh0uBFiwwgJf6WG2+/wsuiQcfRYqdsIMBeW2TMoUbNV4QP4aNOFF6wOFRdS3QS9Lh fqLoP1VCbQhSetxZtUkUFWA7QBKsnaZSdFsYcgD2yTsVo0U7mPLYeqpHV2ir3btUwyig KN0Xsyal+VGtXSYqv3JCetOdhlOdAXRmqy5O8r1w41388ZztCBM5DLd0tQyB0lYSEpLY SoWg== X-Gm-Message-State: AFqh2kqqmiA6JM+rgfqnV6X/B0RZmdNq2A8xWgH2yls6Acwo1SRrD+Vf kKE/q/FnJlN2BTNYb+fLWz/2zAog8ktHD/ERSvU= X-Google-Smtp-Source: AMrXdXtnhd4VlCU4j8kce3g9WRiPF4mmrMqAzv6hxAqB2FlV8Oy7Jma7vBooKux1AoPTmuDM3x+Rcd+kPTyK2sufjcw= X-Received: by 2002:a05:600c:d1:b0:3d9:f629:9043 with SMTP id u17-20020a05600c00d100b003d9f6299043mr214196wmm.122.1673971195069; Tue, 17 Jan 2023 07:59:55 -0800 (PST) In-Reply-To: Received-SPF: pass client-ip=2a00:1450:4864:20::336; envelope-from=yurivkhan@gmail.com; helo=mail-wm1-x336.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=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:142311 Archived-At: On Tue, 17 Jan 2023 at 22:06, Jean Louis wrote: > I learned multiplication in school, we never had impossible > situation of using single argument. As number has to be multiplied by > number. Multiplication table has always 2 arguments. I think we are getting somewhere. We have a common frame of reference: School multiplication. School defines multiplication as a binary operator, that is, taking two arguments. School then says multiplication is associative. That is, it does not matter which order you do it: (a * b) * c =3D a * (b * c). Because of this, it makes sense to talk about the product of a list of numbers: a * b * c * d * e. It has the same value whether you interpret it as (((a * b) * c) * d) * e or a * (b * (c * (d * e))). You can even say there is a multiplication operator that takes five arguments. Or four arguments. Or three. Or any natural number of arguments. Division, on the other hand, is not associative. If you say a / b / c, people give you a funny look and ask to please clarify whether you mean (a / b) / c or a / (b / c). Time passes. You are now at a university. They tell you zero is a natural number. You recall that funny multiplication operator that takes a natural number of arguments, which has a sound definition due to binary multiplication being associative. Since zero is a natural number, what should be the product of a zero length list of arguments? School had also said multiplying by 1 has the same effect as not multiplying at all. That is, a * 1 =3D a. Also, school had said that for every non-zero a, if a * b =3D a * c, then b =3D c, hadn=E2=80=99t it? Some= where around the time you learned to solve equations. It was called canceling. Let=E2=80=99s look at that a * 1 =3D a. On the left, we have the product of= two numbers. On the right, we have one number, and if we squint at it like this, we can say it=E2=80=99s a product of one number. So these are two products that have a common element. We can cancel it. (Assuming it=E2=80= =99s not zero. But we know that a * 1 =3D a holds for any a, including non-zeros.) Now, on the left, we have 1. On the right=E2=80=A6 we have a product of no numbers. And there is an equality sign in between.