Message-ID:  <199812132226.IAA25846@bigted.maths.uq.edu.au>
Reply-To: Mailing list for the LaTeX3 project
              <LATEX-L@URZ.UNI-HEIDELBERG.DE>
Date:         Mon, 14 Dec 1998 08:26:09 +1000
From: Ken Smith <kgs@MATHS.UQ.EDU.AU>
Sender: Mailing list for the LaTeX3 project
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To: Multiple recipients of list LATEX-L
              <LATEX-L@URZ.UNI-HEIDELBERG.DE>
Subject:      Re: portable LaTeX
Status: R

"William F. Hammond" <hammond@CSC.ALBANY.EDU> wrote
on Sat, 12 Dec 1998 19:00:48 -0500

> Timothy Murphy writes:

> : On Sat, Dec 12, 1998 at 06:05:25PM +0100, Chris Rowley wrote:
> :
> : There is a fundamental question about MathML/XML/OpenMath vs TeX/LaTeX
> : which does not seem to me to have been answered here.
> :
> : As I understand it, *ML _parses_ (or tries to parse) maths,

> No.

> : while Knuth in his wisdom decided this was impractical.
> : For example, if I write $AB = CD$
> : this might refer to variables AB,CD (perhaps line segments)
> : or it might refer to products of 4 variables A,B,C,D;

> I would suggest that in a latex-like document preamble one declare,
> with something like "\mathsym" the symbols A, B, C, D either as having
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> a type such as "vertex" or else having a type such as "element of an
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> additive group".
  ^^^^^^^^^^^^^^

This would mean that you would restrict the use of A to have one
particular meaning throughout the document.  This is quite
unrealistic, in almost any area of mathematics.

It might be possible to get away with this if there was some way of
specifying the font (or something similar) in the preamble, so that
\textrm{A}, \textrm{\textsl{A}}, \textrm{\textit{A}},
\textrm{\textbf{A}}, \textsf{A}, ... all meant something different,
and could be handled appropriately.

The thought of this sent my mind back to reading "The non-linear field
theories of mechanics" by Truesdell and Noll.  The authors try to use
one symbol to mean one and only one thing throughout the book.  The
result is a large number of pages simply describing the notation, and
a multiplicity of fonts in several languages.  I found the book almost
unreadable, simply because in the middle of some tricky bit of
analysis I had to refer to the notation npages to see just what was
under discussion.

> In either case to obtain recognition of the typed symbols, one should
> in the body use $A B = C D$ if either "AB" or "CD" is a symbol as
> declared by another \mathsym.  Absent a mathsym declaration the string
> "AB" in a math zone would be equivalent, by tradition, to "A B".

As I point out above, it's not quite as simple as this.

]rest deleted]

>                                    -- Bill

Ken Smith
kgs@maths.uq.edu.au