Received: from webgate.proteosys.de (mail.proteosys-ag.com [62.225.9.49]) by lucy.proteosys (8.11.0/8.9.3/SuSE Linux 8.9.3-0.1) with ESMTP id f4IFTef14623 for ; Fri, 18 May 2001 17:29:40 +0200 Received: by webgate.proteosys.de (8.11.0/8.11.0) with ESMTP id f4IFTe713185 . for ; Fri, 18 May 2001 17:29:40 +0200 Received: from mail.Uni-Mainz.DE (mailserver1.zdv.Uni-Mainz.DE [134.93.8.30]) by mailgate1.zdv.Uni-Mainz.DE (8.11.0/8.10.2) with ESMTP id f4IFTcU27823 for ; Fri, 18 May 2001 17:29:38 +0200 (MET DST) MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C0DFAF.5AAE0A00" Received: from mailgate2.zdv.Uni-Mainz.DE (mailgate2.zdv.Uni-Mainz.DE [134.93.8.57]) by mail.Uni-Mainz.DE (8.9.3/8.9.3) with ESMTP id RAA23574 for ; Fri, 18 May 2001 17:29:38 +0200 (MEST) X-MimeOLE: Produced By Microsoft Exchange V6.5 Received: from mail.listserv.gmd.de (mail.listserv.gmd.de [192.88.97.5]) by mailgate2.zdv.Uni-Mainz.DE (8.11.0/8.10.2) with ESMTP id f4IFTb028721 for ; Fri, 18 May 2001 17:29:37 +0200 (MET DST) Received: from mail.listserv.gmd.de (192.88.97.5) by mail.listserv.gmd.de (LSMTP for OpenVMS v1.1a) with SMTP id <8.51C7BAF8@mail.listserv.gmd.de>; Fri, 18 May 2001 17:27:47 +0200 Received: from RELAY.URZ.UNI-HEIDELBERG.DE by RELAY.URZ.UNI-HEIDELBERG.DE (LISTSERV-TCP/IP release 1.8b) with spool id 495999 for LATEX-L@RELAY.URZ.UNI-HEIDELBERG.DE; Fri, 18 May 2001 17:29:28 +0200 Received: from ix.urz.uni-heidelberg.de (mail.urz.uni-heidelberg.de [129.206.119.234]) by relay.urz.uni-heidelberg.de (8.8.8/8.8.8) with ESMTP id RAA13902 for ; Fri, 18 May 2001 17:29:27 +0200 (MET DST) Received: from relay.uni-heidelberg.de (relay.uni-heidelberg.de [129.206.100.212]) by ix.urz.uni-heidelberg.de (8.8.8/8.8.8) with ESMTP id RAA28538 for ; Fri, 18 May 2001 17:29:27 +0200 Received: from abel.math.umu.se (abel.math.umu.se [130.239.20.139]) by relay.uni-heidelberg.de (8.10.2+Sun/8.10.2) with ESMTP id f4IFTQj11041 for ; Fri, 18 May 2001 17:29:26 +0200 (MET DST) Received: from [130.239.20.144] (mac144.math.umu.se [130.239.20.144]) by abel.math.umu.se (8.9.2/8.9.2) with ESMTP id RAA01125 for ; Fri, 18 May 2001 17:26:04 +0200 (CEST) In-Reply-To: References: <200105161742.MAA02503@riemann.math.twsu.edu> Return-Path: X-Sender: lars@abel.math.umu.se x-mime-autoconverted: from quoted-printable to 8bit by relay.urz.uni-heidelberg.de id RAA13903 Content-class: urn:content-classes:message Subject: Re: Multilingual Encodings Summary 2.2 Date: Fri, 18 May 2001 16:29:26 +0100 Message-ID: X-MS-Has-Attach: X-MS-TNEF-Correlator: From: =?iso-8859-1?Q?Lars_Hellstr=F6m?= Sender: "Mailing list for the LaTeX3 project" To: "Multiple recipients of list LATEX-L" Reply-To: "Mailing list for the LaTeX3 project" Status: R X-Status: X-Keywords: X-UID: 4082 This is a multi-part message in MIME format. ------_=_NextPart_001_01C0DFAF.5AAE0A00 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable At 19.17 +0200 2001-05-17, Hans Aberg wrote: >At 18:59 +0200 2001/05/17, Lars Hellstr=F6m wrote: >>>The \epsilon and \varepsilon are definitely semantically different in >>>(pure) math, >> >>Are they? Please give a verifiable example! > >What do you mean? I started with grad math in the middle of the = seventies, >and I have never myself or met any other thinking of them as being the = same. > Perhaps you having started at that particular time (during the typographical night when the typewriter reigned) is where the problem is = to be found; we've been talking about different things. Considering that: At 19.36 +0200 2001-05-17, Hans Aberg wrote: > >Here are two examples: > $\epsilon\varepsilon R$ > $\varepsilon R$ > >Today one would probably write one of > $\epsilon\in R$ > $\varepsilon\in R$ >(perhaps with $R$ in black-board bold). With TeX, the set membership relation symbol has _always_ been \in, not \epsilon, but appearently you haven't used it enough to take that distinction for granted. I'm not arguing that \in and \epsilon should be identified (as they are clearly semantically distinct), I'm arguing that \epsilon and \varepsilon (which are both greek letters called "epsilon" when a formula is read aloud) should be identified in the internal LaTeX representation of math characters. It is true that they have distinct code points in Unicode, but so does = many other glyphic variants of math symbols (such as U+2208, ELEMENT OF, and U+220A, SMALL ELEMENT OF) for which there are no distinct = representations in LaTeX today. Furthermore the only other symbol which appears under = the same heading as the second Unicode epsilon (U+03F5 GREEK LUNATE EPSILON SYMBOL, which looks like TeX's \epsilon in the code charts) is U+03F4 (GREEK CAPITAL THETA SYMBOL), whose only difference to the proper Theta U+0398 (GREEK CAPITAL LETTER THETA) is that the horizontal line goes all the way to the ring. Is that a reason to give this variant \Theta glyph = its own internal representation in LaTeX? I don't think so. Recall that the Symbol font (which should rank as one of the more = important sources of mathematical symbols after Computer Modern) only contains one epsilon glyph; thus you cannot in a math font set-up based on that font provide visually distinct renderings of \epsilon and \varepsilon. Then = it is better have one command \epsilon and use some other mechanism for selecting how it should be rendered, if the font set-up provides alternative ways of rendering it. Finally, a theory about the origin of the two epsilons in Computer = Modern. While doing some checks in pre-TeX literature on mathematical = typography, I came across the following piece of text ending a paragraph that = discussed how one distinguishes between (what would be TeXified as) \varepsilon = and \in: An additional complication is that, particularly in manuscripts in English, the sign $\epsilon$ does not necessarily mean $\in$, instead it can just as well mean $\varepsilon$, since this letter has a more ``grotesque'' shape in English typefaces. [My translation and TeXification, assuming CM math.] With such a traditional difference between English and, say, continental European typographical traditions, it wouldn't be surprising if Knuth included \varepsilon to please mathematicians who were accustomed to having the epsilon letter and set membership symbol more distinct than \epsilon and \in are in Computer Modern. Perhaps someone who has a copy of the book Computer Modern Typefaces can verify or dismiss this theory. Lars Hellstr=F6m ------_=_NextPart_001_01C0DFAF.5AAE0A00 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: Multilingual Encodings Summary 2.2

At 19.17 +0200 2001-05-17, Hans Aberg wrote:
>At 18:59 +0200 2001/05/17, Lars Hellstr=F6m = wrote:
>>>The \epsilon and \varepsilon are = definitely semantically different in
>>>(pure) math,
>>
>>Are they? Please give a verifiable = example!
>
>What do you mean? I started with grad math in the = middle of the seventies,
>and I have never myself or met any other thinking = of them as being the same.
>

Perhaps you having started at that particular time = (during the
typographical night when the typewriter reigned) is = where the problem is to
be found; we've been talking about different things. = Considering that:

At 19.36 +0200 2001-05-17, Hans Aberg wrote:
>
>Here are two examples:
>  $\epsilon\varepsilon R$
>  $\varepsilon R$
>
>Today one would probably write one of
>  $\epsilon\in R$
>  $\varepsilon\in R$
>(perhaps with $R$ in black-board bold).

With TeX, the set membership relation symbol has = _always_ been \in, not
\epsilon, but appearently you haven't used it enough = to take that
distinction for granted. I'm not arguing that \in and = \epsilon should be
identified (as they are clearly semantically = distinct), I'm arguing that
\epsilon and \varepsilon (which are both greek = letters called "epsilon"
when a formula is read aloud) should be identified in = the internal LaTeX
representation of math characters.

It is true that they have distinct code points in = Unicode, but so does many
other glyphic variants of math symbols (such as = U+2208, ELEMENT OF, and
U+220A, SMALL ELEMENT OF) for which there are no = distinct representations
in LaTeX today. Furthermore the only other symbol = which appears under the
same heading as the second Unicode epsilon (U+03F5 = GREEK LUNATE EPSILON
SYMBOL, which looks like TeX's \epsilon in the code = charts) is U+03F4
(GREEK CAPITAL THETA SYMBOL), whose only difference = to the proper Theta
U+0398 (GREEK CAPITAL LETTER THETA) is that the = horizontal line goes all
the way to the ring. Is that a reason to give this = variant \Theta glyph its
own internal representation in LaTeX? I don't think = so.

Recall that the Symbol font (which should rank as one = of the more important
sources of mathematical symbols after Computer = Modern) only contains one
epsilon glyph; thus you cannot in a math font set-up = based on that font
provide visually distinct renderings of \epsilon and = \varepsilon. Then it
is better have one command \epsilon and use some = other mechanism for
selecting how it should be rendered, if the font = set-up provides
alternative ways of rendering it.

Finally, a theory about the origin of the two epsilons = in Computer Modern.
While doing some checks in pre-TeX literature on = mathematical typography, I
came across the following piece of text ending a = paragraph that discussed
how one distinguishes between (what would be TeXified = as) \varepsilon and
\in:

  An additional complication is that, = particularly in manuscripts in
  English, the sign $\epsilon$ does not = necessarily mean $\in$, instead
  it can just as well mean $\varepsilon$, since = this letter has a more
  ``grotesque'' shape in English = typefaces.

[My translation and TeXification, assuming CM math.] = With such a
traditional difference between English and, say, = continental European
typographical traditions, it wouldn't be surprising = if Knuth included
\varepsilon to please mathematicians who were = accustomed to having the
epsilon letter and set membership symbol more = distinct than \epsilon and
\in are in Computer Modern. Perhaps someone who has a = copy of the book
Computer Modern Typefaces can verify or dismiss this = theory.

Lars Hellstr=F6m

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