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 f4JEhRf17948 for ; Sat, 19 May 2001 16:43:27 +0200 Received: by webgate.proteosys.de (8.11.0/8.11.0) with ESMTP id f4JEhE718153 . for ; Sat, 19 May 2001 16:43:14 +0200 Received: from mail.Uni-Mainz.DE (mailserver1.zdv.Uni-Mainz.DE [134.93.8.30]) by mailgate2.zdv.Uni-Mainz.DE (8.11.0/8.10.2) with ESMTP id f4JEhD023282 for ; Sat, 19 May 2001 16:43:13 +0200 (MET DST) MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C0E072.10419180" 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 QAA06098 for ; Sat, 19 May 2001 16:43:13 +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 f4JEhD023278 for ; Sat, 19 May 2001 16:43:13 +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 <5.032AC479@mail.listserv.gmd.de>; Sat, 19 May 2001 16:41:27 +0200 Received: from RELAY.URZ.UNI-HEIDELBERG.DE by RELAY.URZ.UNI-HEIDELBERG.DE (LISTSERV-TCP/IP release 1.8b) with spool id 495904 for LATEX-L@RELAY.URZ.UNI-HEIDELBERG.DE; Sat, 19 May 2001 16:43:09 +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 QAA22486 for ; Sat, 19 May 2001 16:43:07 +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 QAA47290 for ; Sat, 19 May 2001 16:43:08 +0200 Received: from mail.umu.se (custer.umdac.umu.se [130.239.8.14]) by relay.uni-heidelberg.de (8.10.2+Sun/8.10.2) with ESMTP id f4JEh8j24413 for ; Sat, 19 May 2001 16:43:08 +0200 (MET DST) Received: from [130.239.137.13] (mariehemsv093.sn.umu.se [130.239.137.13]) by mail.umu.se (8.8.8/8.8.8) with ESMTP id QAA09581 for ; Sat, 19 May 2001 16:43:06 +0200 (MET DST) 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 QAA22487 Content-class: urn:content-classes:message Subject: Re: Multilingual Encodings Summary 2.2 Date: Sat, 19 May 2001 15:43:05 +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: 4084 This is a multi-part message in MIME format. ------_=_NextPart_001_01C0E072.10419180 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable At 12.19 +0200 2001-05-19, Hans Aberg wrote: >At 17:29 +0200 2001/05/18, Lars Hellstr=F6m wrote: >>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. > >The reason one is getting stuck with it is for backwards compatibility, = and Indeed. \epsilon and \varepsilon could probably not be identified = earlier than in LaTeX3. >further there is no guarantee that mathematicians will use the symbols = the >way you dictate. You mean saying \in for the set membership relation rather than = \epsilon? \epsilon is just plain wrong (and has always been so) since it generates = an Ord math atom, not a Rel math atom as a relation command should. >Later, one would expect LaTeX, or whatever scientific typesetting = system, >being capable to support them all without restrictions. Plus admitting >future additions. Yes, but not necessarily supporting them by default. There is an = important difference between the default set-up making \epsilon and \varepsilon different, and providing a mechanism that makes it easy to (on a per document basis) add such a distinction. What is provided by the default set-up becomes the minimal core which _all_ set-ups must provide. The larger you make this core, the bigger the effort needed to support it = will be, and the alternatives to the default will be correspondingly fewer. = It's easy to request that all fonts provide everything that is in Unicode if = you anyway would never help with providing anything. >I have seen examples of both types of epsilon being used to denote set >membership, No doubt due to "limitations in past typesetting". >and I have seen examples of both types of epsilon being used as >a small number > 0. You could probably add a whole range of characters >moving from \varepsilon to \epsilon to \in for set membership. That's where I suspect you get it all wrong. You're talking about a = whole range of _glyphs_, in appearence similar to anything between the \varepsilon and the \in of Computer Modern, but they're all the same semantic atom (i.e., character) and thus shouldn't have distinct = internal representations in LaTeX. That at least part of that range of glyphs may also be used to represent another character (the greek letter small epsilon) which should have its own internal representation is another matter. >Knuth, being wise, realized how disparate the use of the symbols are in >math, and introduced a macro symbols system so that anyone can define = them >as they please: The point is that the macro system Knuth created has no internal representation for characters, neither in text nor math---instead it is based on the user specifying what glyph (or combination of glyphs) is desired. LaTeX, by contrast, has an internal representation for = characters as of version 2e, but still uses the Knuthian glyph selection commands = in math. What I argue is that by version 3 of LaTeX there should be an internal math character representation as well. >Further, if you want to make it impossible to use \varepsilon and = \epsilon >side by side in the same document, you will have to make sure that in = all >of the world literature in the past up till now it has never been used = that >way, because that is how the requirements of Unicode were set up. I'm not saying that it should be completely impossible to use them side = by side (even though I would question any attempts to do so), but they shouldn't be provided as distinct characters in the default set-up. >As for the math characters, I do not see there is any point in trying = to >impose equivalences because the way the may be used in math, and it is = just >an unnecessary additional work in implementation. It is very little additional work in the implementation of LaTeX (adding = an OCP which normalizes the input somewhat further than what Unicode = precribes will do), but it saves much (largely unnecessary) work in the implementation of fonts for LaTeX, and thereby it facilitates the = creations of new fonts. Lars Hellstr=F6m ------_=_NextPart_001_01C0E072.10419180 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: Multilingual Encodings Summary 2.2

At 12.19 +0200 2001-05-19, Hans Aberg wrote:
>At 17:29 +0200 2001/05/18, Lars Hellstr=F6m = wrote:
>>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.
>
>The reason one is getting stuck with it is for = backwards compatibility, and

Indeed. \epsilon and \varepsilon could probably not be = identified earlier
than in LaTeX3.

>further there is no guarantee that mathematicians = will use the symbols the
>way you dictate.

You mean saying \in for the set membership relation = rather than \epsilon?
\epsilon is just plain wrong (and has always been so) = since it generates an
Ord math atom, not a Rel math atom as a relation = command should.

>Later, one would expect LaTeX, or whatever = scientific typesetting system,
>being capable to support them all without = restrictions. Plus admitting
>future additions.

Yes, but not necessarily supporting them by default. = There is an important
difference between the default set-up making \epsilon = and \varepsilon
different, and providing a mechanism that makes it = easy to (on a per
document basis) add such a distinction. What is = provided by the default
set-up becomes the minimal core which _all_ set-ups = must provide. The
larger you make this core, the bigger the effort = needed to support it will
be, and the alternatives to the default will be = correspondingly fewer. It's
easy to request that all fonts provide everything = that is in Unicode if you
anyway would never help with providing = anything.

>I have seen examples of both types of epsilon = being used to denote set
>membership,

No doubt due to "limitations in past = typesetting".

>and I have seen examples of both types of epsilon = being used as
>a small number > 0. You could probably add a = whole range of characters
>moving from \varepsilon to \epsilon to \in for = set membership.

That's where I suspect you get it all wrong. You're = talking about a whole
range of _glyphs_, in appearence similar to anything = between the
\varepsilon and the \in of Computer Modern, but = they're all the same
semantic atom (i.e., character) and thus shouldn't = have distinct internal
representations in LaTeX. That at least part of that = range of glyphs may
also be used to represent another character (the = greek letter small
epsilon) which should have its own internal = representation is another
matter.

>Knuth, being wise, realized how disparate the use = of the symbols are in
>math, and introduced a macro symbols system so = that anyone can define them
>as they please:

The point is that the macro system Knuth created has = no internal
representation for characters, neither in text nor = math---instead it is
based on the user specifying what glyph (or = combination of glyphs) is
desired. LaTeX, by contrast, has an internal = representation for characters
as of version 2e, but still uses the Knuthian glyph = selection commands in
math. What I argue is that by version 3 of LaTeX = there should be an
internal math character representation as = well.

>Further, if you want to make it impossible to use = \varepsilon and \epsilon
>side by side in the same document, you will have = to make sure that in all
>of the world literature in the past up till now = it has never been used that
>way, because that is how the requirements of = Unicode were set up.

I'm not saying that it should be completely impossible = to use them side by
side (even though I would question any attempts to do = so), but they
shouldn't be provided as distinct characters in the = default set-up.

>As for the math characters, I do not see there is = any point in trying to
>impose equivalences because the way the may be = used in math, and it is just
>an unnecessary additional work in = implementation.

It is very little additional work in the = implementation of LaTeX (adding an
OCP which normalizes the input somewhat further than = what Unicode precribes
will do), but it saves much (largely unnecessary) = work in the
implementation of fonts for LaTeX, and thereby it = facilitates the creations
of new fonts.

Lars Hellstr=F6m

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