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 08:50:07 +0100 Message-ID: <87v8l49t8w.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> 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="8559"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) To: help-gnu-emacs@gnu.org Cancel-Lock: sha1:3zYDcQ36f6TJPQm2CQ3vthP+OlM= Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Wed Jan 18 08:51:18 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 1pI3E5-00022R-OK for geh-help-gnu-emacs@m.gmane-mx.org; Wed, 18 Jan 2023 08:51:17 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pI3DC-0001Gf-Sn; Wed, 18 Jan 2023 02:50:22 -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 1pI3DA-0001GV-J2 for help-gnu-emacs@gnu.org; Wed, 18 Jan 2023 02:50:20 -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 1pI3D8-0001gQ-TW for help-gnu-emacs@gnu.org; Wed, 18 Jan 2023 02:50:20 -0500 Original-Received: from list by ciao.gmane.io with local (Exim 4.92) (envelope-from ) id 1pI3D5-0000oB-Sd for help-gnu-emacs@gnu.org; Wed, 18 Jan 2023 08:50:15 +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: -15 X-Spam_score: -1.6 X-Spam_bar: - X-Spam_report: (-1.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.25, 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:142347 Archived-At: Michael Heerdegen writes: > Óscar Fuentes writes: > >> The languages that use the concept of partially applied function usually >> have no support for variadic functions, so the duality problem you refer >> to is not an issue. > > Interesting. I do not know many other languages. > > I see your point now: while I wrote about the procedure of finding an > interpretation [of the technical or mathematical semantics of a formula] > in the real world [this is what had been ongoing: Ferraris etc], you > mention that even the technical/theoretical semantics of a formula like > (*) can be different. This is an interesting point, especially since > terms like "right" and "wrong" had been used. > > Although I think the "meaning" of the expression (*) in Elisp is clear, > it describes a mathematical term, so the question, asked specifically > for Elisp, has to be answered using the mathematical background. In my > understanding the OP asked specifically about the empty algebraic > product. I was prompted to enter the discussion when I saw your reference to Mathematics. As almost every other math-related thing in computers, Elisp's + is a toy representation of Sigma. And then the relevant characteristics of Sigma for this discussion are a convention among practitioners, not a proper mathematical fact. Although it is possible that the implementors were inspired by Sigma, I think it is more probable that they made + variadic because s-exps like (+ (+ 1 2) 3) are awkward and then extended the function with support for 0 and 1 arguments because they are convenient when defining macros.