From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp10.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms0.migadu.com with LMTPS id sAwLKU/H1mEHLQAAgWs5BA (envelope-from ) for ; Thu, 06 Jan 2022 11:41:19 +0100 Received: from aspmx1.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp10.migadu.com with LMTPS id UGjVIU/H1mF6AgEAG6o9tA (envelope-from ) for ; Thu, 06 Jan 2022 11:41:19 +0100 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by aspmx1.migadu.com (Postfix) with ESMTPS id 4568D103D9 for ; Thu, 6 Jan 2022 11:41:19 +0100 (CET) Received: from localhost ([::1]:42732 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1n5QCs-00067J-Ai for larch@yhetil.org; Thu, 06 Jan 2022 05:41:18 -0500 Received: from eggs.gnu.org ([209.51.188.92]:59928) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n5QB6-0003xO-6K for guix-devel@gnu.org; Thu, 06 Jan 2022 05:39:28 -0500 Received: from world.peace.net ([64.112.178.59]:35392) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n5QB4-00045b-6s for guix-devel@gnu.org; Thu, 06 Jan 2022 05:39:27 -0500 Received: from mhw by world.peace.net with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1n5QAr-00085T-UY; Thu, 06 Jan 2022 05:39:14 -0500 From: Mark H Weaver To: Liliana Marie Prikler , zimoun , guix-devel@gnu.org Subject: Re: On raw strings in commit field In-Reply-To: <47d713d7bbfb4673c25398e0d6c62a47b4f490f4.camel@gmail.com> References: <6e451a878b749d4afb6eede9b476e5faabb0d609.camel@gmail.com> <86y243kdoo.fsf@gmail.com> <899587fb6a76ddfa37d197d3d0fd23cdc7ad8592.camel@gmail.com> <867dbmi7pf.fsf@gmail.com> <3d448fe42f0c43574db96fa26aecd7da5fd5a95d.camel@gmail.com> <877dbkmjm9.fsf@netris.org> <762e9fb7116c442bf0f8f63221bf32fa2b77f2cf.camel@gmail.com> <87y240kq2i.fsf@netris.org> <9362c6fb7e34ded5d009c3f79cd18300d6cd539c.camel@gmail.com> <87r19rkx9h.fsf@netris.org> <87r19pbv8y.fsf@netris.org> <87mtkcbedc.fsf@netris.org> <3f947861672144d202a8c736d5e8f2b905c31b66.camel@gmail.com> <871r1nawz8.fsf@netris.org> <87h7aia5ug.fsf@netris.org> <47d713d7bbfb4673c25398e0d6c62a47b4f490f4.camel@gmail.com> Date: Thu, 06 Jan 2022 05:38:30 -0500 Message-ID: <87a6g99mim.fsf@netris.org> MIME-Version: 1.0 Content-Type: text/plain Received-SPF: pass client-ip=64.112.178.59; envelope-from=mhw@netris.org; helo=world.peace.net 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_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: guix-devel@gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+larch=yhetil.org@gnu.org Sender: "Guix-devel" X-Migadu-Flow: FLOW_IN X-Migadu-Country: US ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1641465679; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references:list-id:list-help:list-unsubscribe: list-subscribe:list-post; bh=BRCsAUiwkD5ZKSNWha4jxc7AXA8smKYiWs8q4xeAnQA=; b=JcA/9olZl2kiafY+KnhjNjqli2LlCK6R5SUGXVXqUIkS2RJPULoCrRtkWMH1dvvpN2pF8d G9TDh1KDWMB+eGNOjduXRH/Ui868o4ggEoT5hqfuwK/OOOiTgN9vsaSwDt8VFejwo+ITp4 FHdRARjD8UXBmzdnn97aZWMUbFq9z/HEoE+a2hXeFwZuPLF/Xl7SMD6T/Uz/AHzAQFBY1d LmCiYfoO6XDlN1vhSr6x3vVZTDWnPnkNwm2CKjFKd2wuqTbDawysRrxY6NSimkBmQY3a6I fPOxvVj8Iy9W+Y8Zh2jb3GozeOxpQ0MRyQ6RNoa10Iz+3eLp9XF6OdRFL2KzwA== ARC-Seal: i=1; s=key1; d=yhetil.org; t=1641465679; a=rsa-sha256; cv=none; b=ujaqdaqy3PFks4b3yLVYK+Y+cezhY/VvYiO97ODLzTrfb5BoB9hUJRC0hsohIMhJoR6NUb 8gU+Z1L3NKp2k9B9EJtoyKc5buRNwVVZbiWGbsHBELNOMUBXtNVG0sZDgX+RlSU7FPYFhF SyiP1jSH8TOEDaAvXjCHa0n7LGGzccwSmM+KcCV8+5+53hXoZUC15necQCbG0oCIv2iVVt 8dDd8t5TaR5gYG9heWv9/LwI4w0reQhNBVv0bA5A2j6gHiGiOwAhHjuISmNZwln9Qyo2S1 J6nEb5xHj+mAycRSDyETw7UZnhMraT7xHZuw+7KwQAe7ma/mNBY9olx05ojC1Q== ARC-Authentication-Results: i=1; aspmx1.migadu.com; dkim=none; dmarc=none; spf=pass (aspmx1.migadu.com: domain of "guix-devel-bounces+larch=yhetil.org@gnu.org" designates 209.51.188.17 as permitted sender) smtp.mailfrom="guix-devel-bounces+larch=yhetil.org@gnu.org" X-Migadu-Spam-Score: -3.10 Authentication-Results: aspmx1.migadu.com; dkim=none; dmarc=none; spf=pass (aspmx1.migadu.com: domain of "guix-devel-bounces+larch=yhetil.org@gnu.org" designates 209.51.188.17 as permitted sender) smtp.mailfrom="guix-devel-bounces+larch=yhetil.org@gnu.org" X-Migadu-Queue-Id: 4568D103D9 X-Spam-Score: -3.10 X-Migadu-Scanner: scn1.migadu.com X-TUID: PciABWoHJfMy Hi Liliana, Liliana Marie Prikler writes: > it ought to have been comparatively easy to infer that I was talking > about push actions (plural) as sequences, not as individual push > actions like you've used for your proof. It makes no difference, because the set of push actions is closed under sequential composition. Moreover, the argument in my proof applies to *any* kind of action that can be communicated over a digital communications channel in finite time. > From here on, I will assume that each individual push action is finite > as you did, but I don't think that using communications of finite > length are a helpful building block here. Really? You don't think communications of finite length are a helpful building block here? Note that in the real world, every observable time interval is finite. > Porting Git to Turing > Machines would have the effect of allowing an infinite tape shared > between multiple machines and they could possibly run forever. I'm sorry, I thought we were talking about "Git" as it exists in the real world. Please recall that the motivation for my proof was to refute the following claim of yours from a few messages ago: >> How about pointing out what acts as the diagonal in your reasoning? > >If you are talking specifically about the uncountability of real >numbers, that'd be quite deep down (as in an uncountability of push >actions to a particular Git repo, particularly if we also allow >reinitialization). You referred to "Git" here. That's why my proof was about Git. You didn't say that you were talking about some theoretical variant of Git that supports "push actions" that literally *never* end, and that runs on a theoretical machine with infinite memory that can never be built. > As we're trying to generalize your proof for a single push action to > be chosen among a finite set to all communications to a series of push > actions, we do encounter a problem if we were to encode this as a mere > list of push actions. This can be done by a rather simple Cantor > proof: The set of lists of a particular type T which admits at least > two values is uncountable (a list of booleans can be directly mapped > to a binary number and thus Cantor's original proof applied). No, that's incorrect. The set of lists of booleans is countable. Moreover, for any type T, if the set of objects of type T is countable, then the set of _lists_ of objects of type T is also countable. Note that lists are finite, by definition. If you intend to claim that by "push actions", you meant to include infinite streams of push actions: this has no relevance to the real world. Even if we live in an open universe, the fact remains that at any arbitrary point in time, the age of any git repository is always finite. Therefore, no one can ever observe the result of an infinite-length "push action" in the real world. They can only ever observe the result of some finite prefix of that so-called "push action". * * * I'm sorry, but I'm growing tired of this discussion. I suppose you will want to have the last word. I'll try to resist the temptation to correct any errors in it, but my silence should not be interpreted as acceptance of your future claims. Regards, Mark -- Disinformation flourishes because many people care deeply about injustice but very few check the facts. Ask me about .