From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/10251 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Johannes Huebschmann Newsgroups: gmane.science.mathematics.categories Subject: Re: Looking for a reference Date: Wed, 15 Jul 2020 10:34:51 +0200 (CEST) Message-ID: References: Reply-To: Johannes Huebschmann 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="39377"; mail-complaints-to="usenet@ciao.gmane.io" Cc: "categories@mta.ca list" To: porst Original-X-From: majordomo@rr.mta.ca Fri Jul 17 02:07:22 2020 Return-path: Envelope-to: gsmc-categories@m.gmane-mx.org Original-Received: from smtp2.mta.ca ([198.164.44.55]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jwDuL-000A7C-TJ for gsmc-categories@m.gmane-mx.org; Fri, 17 Jul 2020 02:07:22 +0200 Original-Received: from rr.mta.ca ([198.164.44.159]:60224) by smtp2.mta.ca with esmtp (Exim 4.80) (envelope-from ) id 1jwDtx-0000sM-6K; Thu, 16 Jul 2020 21:06:57 -0300 Original-Received: from majordomo by rr.mta.ca with local (Exim 4.92.1) (envelope-from ) id 1jwDtP-0004w3-IK for categories-list@rr.mta.ca; Thu, 16 Jul 2020 21:06:23 -0300 In-Reply-To: Precedence: bulk Xref: news.gmane.io gmane.science.mathematics.categories:10251 Archived-At: This is implicit in Ch. 2 of @book{0004.36904, author=3D"Reidemeister, Kurt", title=3D"{Einf\"uhrung in die kombinatorische Topologie.}", language=3D"German", publisher=3D"{Braunschweig: Friedr. Vieweg \& Sohn A.-G. XII, 209 S. }", year=3D"1932", keywords=3D"{topology}", } Every group is a homomorphic image of a free group. Presumably it also implicit in @Article{zbMATH02581122, Author =3D {O. {Schreier}}, Title =3D {{Die Untergruppen der freien Gruppen.}}, FJournal =3D {{Abhandlungen aus dem Mathematischen Seminar der Universit\"= at Hamburg}}, Journal =3D {{Abh. Math. Semin. Univ. Hamb.}}, ISSN =3D {0025-5858; 1865-8784/e}, Volume =3D {5}, Pages =3D {161--183}, Year =3D {1927}, Publisher =3D {Springer, Berlin/Heidelberg}, Language =3D {German}, Zbl =3D {53.0110.01} } Johannes HUEBSCHMANN Johannes Professeur =C3=A9m=C3=A9rite Universit=C3=A9 de Lille - Sciences et Technologies=20 D=C3=A9partement de Math=C3=A9matiques CNRS-UMR 8524 Laboratoire Paul Painlev=C3=A9 Labex CEMPI (ANR-11-LABX-0007-01) 59 655 VILLENEUVE D'ASCQ Cedex/France http://math.univ-lille1.fr/~huebschm Johannes.Huebschmann@univ-lille.fr ----- Mail original ----- De: "porst" =C3=80: "categories@mta.ca list" Envoy=C3=A9: Mardi 14 Juillet 2020 18:08:51 Objet: categories: Looking for a reference Dear all, If I am not mistaken the characterization of free groups by its universal p= roperty has first been shown in the late 1920s. Does anybody know a referen= ce? Hans-E. Porst -- Hans-E. Porst porst@uni-bremen.de [For admin and other information see: http://www.mta.ca/~cat-dist/ ]