From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp11.migadu.com ([2001:41d0:2:bcc0::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms5.migadu.com with LMTPS id GM2WODZdqmIqcAEAbAwnHQ (envelope-from ) for ; Thu, 16 Jun 2022 00:29:10 +0200 Received: from aspmx1.migadu.com ([2001:41d0:2:bcc0::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp11.migadu.com with LMTPS id OD+RODZdqmLhBQAA9RJhRA (envelope-from ) for ; Thu, 16 Jun 2022 00:29:10 +0200 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 A7FEF339AD for ; Thu, 16 Jun 2022 00:29:10 +0200 (CEST) Received: from localhost ([::1]:37324 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1o1bVd-00018j-LH for larch@yhetil.org; Wed, 15 Jun 2022 18:29:09 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46458) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o1bVF-00018b-Mq for guix-devel@gnu.org; Wed, 15 Jun 2022 18:28:45 -0400 Received: from albert.telenet-ops.be ([2a02:1800:110:4::f00:1a]:51920) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1o1bVD-0000Po-CK for guix-devel@gnu.org; Wed, 15 Jun 2022 18:28:45 -0400 Received: from ptr-bvsjgyhxw7psv60dyze.18120a2.ip6.access.telenet.be ([IPv6:2a02:1811:8c09:9d00:3c5f:2eff:feb0:ba5a]) by albert.telenet-ops.be with bizsmtp id jaUf270054UW6Th06aUf1y; Thu, 16 Jun 2022 00:28:39 +0200 Message-ID: Subject: Re: how to write services (was: Re: Teams) From: Maxime Devos To: Blake Shaw Cc: guix-devel@gnu.org Date: Thu, 16 Jun 2022 00:28:34 +0200 In-Reply-To: References: <87a6as62r2.fsf@elephly.net> <87ilpfwmi0.fsf@jpoiret.xyz> <877d5j5vng.fsf@trop.in> <87a666663179c883aaa1797b62c3bcb0084d3ebb.camel@gmail.com> <87bkuuyqf9.fsf@elephly.net> <6aca367bce796a4856ef583cc65bfae22d946691.camel@telenet.be> Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-g8ALuDt5CW2xT5STA21T" User-Agent: Evolution 3.38.3-1 MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=telenet.be; s=r22; t=1655332119; bh=k/FpN6EONoqNj2b+29GX4rdmAVR76rhDezvwSvfb6qw=; h=Subject:From:To:Cc:Date:In-Reply-To:References; b=m0ULo3W8rtLlj7Ert8kKNbtYnOoMgxFUTsOwG0iPTVvIOK8qXJXm+3YdQwYE9MrTn HfJZuhYXnSGKw6HGrhISLf7mKRGTlcRwYl6K57bsN0c2SIk9GP7BKxsvgmS7pIfCIp Im4lzktb3TqIbXU98sKxfswIkBr66VbA9ttMEbbW96ARoUmZWbz6qH8CSbC0Q7HJX3 SwLXlS/4GrJf2dSd9Fn9pxMGEDH3+3KRIbxDpC63kp54nNT3FOP6EHU6FKFbfg9jSA d9VF4VUO6AyRTn9shL0mQ3lGSItRdmK1cagXKkYDlRRAVV5RWjHqg1s37HxI//ywvJ ccWKFeGvy5Jzg== Received-SPF: pass client-ip=2a02:1800:110:4::f00:1a; envelope-from=maximedevos@telenet.be; helo=albert.telenet-ops.be X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 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_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 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-To: larch@yhetil.org X-Migadu-Country: US ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1655332150; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc: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:dkim-signature; bh=k/FpN6EONoqNj2b+29GX4rdmAVR76rhDezvwSvfb6qw=; b=PNrqtxlYQr7lI4vaa/FYTg2CK5jh4/ob+abLOysPXCAq93944vnHXgPkFIsgUixd/VYsTu 8yAgiMQ4ttodbHlTJWXy2wvy5dZ/vz/bTySWjeGhZxRlTnL0YVyYNJGLEpyNodFkmdHna+ SvE2X+Zewf2tXQqJla98cMtd4y5I2xdieOJl348FrwRznFZTUdmTi5LBz7QYMOuEoCBWGw i0xzhMQ43+R/JhHeT+mNH2Akau5OZccn3x39JDlP6nSFkmaEEJBCiEnjVVEBRrORAOK02R kBieYRSHNWmwQD9Vbus9HwH599lst2VhPmFhdJtdAk9rwy4XS9bj84Gb61oOkg== ARC-Seal: i=1; s=key1; d=yhetil.org; t=1655332150; a=rsa-sha256; cv=none; b=RhjXIxfCs2j8TeDWqDKAJjQzlqOJ4twJZkbx69XdGQTnzfy5mIkDYSfrDeahzwzBzhANSc wzcWx48ChdFgbz+tJLhzFd0ozvy1xYm16l1i/RwZBviNGTzna+IrP0aXmGgO/BfMDtZ4t2 kmWefPdChXNdgH9L+v4UKBO1cjnnDCqpxzz5AIeXHvVzHzKnjQ+otiSpxFQkI6wChxeZ7R NUtNs7bno8AsMs4293jy77i2LLaKZsDkpm1qmzqCrBJb7bF0GUOmNa+S2Artg6EW4GvwB1 Nt82+N2B5JxuONX57jda0dBzRcDJQGtXA6PcNVFu1Eo/CZVARuYNG4UbQUr4Xg== ARC-Authentication-Results: i=1; aspmx1.migadu.com; dkim=pass header.d=telenet.be header.s=r22 header.b=m0ULo3W8; dmarc=pass (policy=none) header.from=telenet.be; 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: -11.59 Authentication-Results: aspmx1.migadu.com; dkim=pass header.d=telenet.be header.s=r22 header.b=m0ULo3W8; dmarc=pass (policy=none) header.from=telenet.be; 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: A7FEF339AD X-Spam-Score: -11.59 X-Migadu-Scanner: scn0.migadu.com X-TUID: DJ4/B5ApVLln --=-g8ALuDt5CW2xT5STA21T Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Blake Shaw schreef op wo 15-06-2022 om 21:40 [+0000]: > On the contrary, lets say I'm writing an intro book on CT. If I'm > demonstrating something trivial, say the initial object, I'm not > going to refer to it as "an initial-like object" for the sake of > generality. Neither does Guix? If you're in a context where only the basic object (in this case, your demonstration the initial object) is used, just talk about the basic object. But in a later section where you generalize things to =E2=80=98initial-like objects=E2=80=99 (whatever that = would be in CT, I don't know any CT), you talk about =E2=80=98initial-like objects=E2= =80=99, not =E2=80=98initial object and initial-like objects=E2=80=99. For an example from another domain, consider groups in algebra. In group theory, we have e.g. the fundamental theorem on homomorphisms. Wikipedia formulates this as: Given two groups G and H and a group homomorphism f : G =E2=86=92 H, let K = be a normal subgroup in G and =CF=86 the natural surjective homomorphism G =E2= =86=92 G/K (where G/K is the quotient group of G by K). If K is a subset of ker(f) then there exists a unique homomorphism h: G/K =E2=86=92 H such that f =3D = h=E2=88=98=CF=86. An equivalent statement could be made by replacing =E2=80=98given a group= =E2=80=99 by =E2=80=98given an Abelian group or a group=E2=80=99: Given two Abelian groups or groups G and H and a group homomorphism f : G =E2=86=92 H, let K be an Abelian normal subgroup or normal subgroup in G = and =CF=86 the natural surjective homomorphism G =E2=86=92 G/K (where G/K is th= e quotient group of G by K). If K is a subset of ker(f) then there exists a unique homomorphism h: G/K =E2=86=92 H such that f =3D h=E2=88=98=CF=86.= =E2=80=99 But why do such a pointless thing, wouldn't just talking about groups instead of =E2=80=98Abelian groups or groups=E2=80=99 be much simpler? TBC: here =E2=80=98file-like object=E2=80=99 =E2=89=83 =E2=80=98group=E2=80= =99 and =E2=80=98file=E2=80=99 =3D =E2=80=98Abelian group=E2=80=99. Greetings, Maxime. --=-g8ALuDt5CW2xT5STA21T Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iI0EABYKADUWIQTB8z7iDFKP233XAR9J4+4iGRcl7gUCYqpdEhccbWF4aW1lZGV2 b3NAdGVsZW5ldC5iZQAKCRBJ4+4iGRcl7u5bAQDKCuiAka/jg4b1a9NZb0QpJzHL /21dw95mI0JuUcrvHAD/f2A0a8QR6QKEbZUYEqH8RAY14Q2cA5RoITrC0X7E2gA= =o6f1 -----END PGP SIGNATURE----- --=-g8ALuDt5CW2xT5STA21T--