# [texhax] Latex: dumbing down? (fwd)

Uwe Lück uwe.lueck at web.de
Sun Sep 10 13:49:00 CEST 2006

First, a pointer concerning philosophical issues:
I'd like to draw to attention what Claudio Beccari
wrote on LaTeX vs. Plain TeX in TUBboat 24-2 p. 277
(in a review of the 2nd edition of the LaTeX Companion).

At 17:25 25.08.06, Michael Barr wrote:

>I recently got a paper to copy edit that contained the line
>$(*)\ \ \ \ \ \ \ \ \ some formula$
>with a later reference to formula $(*)$.  Naturally, I changed that to
>$$some formula\eqno(*)$$
>(Actually, first I tried $...\eqno(*)$ but that gave an error message.)
>
>how dangerous it can be to mix plain and latex (why then is nearly the
>entire body of plain incorporated into latex?), but I have never paid the
>least attention to that.  Certainly Leslie Lamport was not rigid on that
>question.  Two pages of his "Latex" was devoted to that question.  As far
>as I can tell from that book as well as the Companion, there is no way, in
>pure latex, to put in (*) as an equation "number".  But this is a
>perfectly reasonable thing to do.
>
>More generally, restricting oneself to "pure" latex, while a good idea for
>a beginner, is too restrictive for someone who wants to get the most out
>of tex.  I am beginning to understand the mentality of a colleague of mine
>who told me that he would never use Latex because Latex does not allow you
>to...(whatever, as a matter of fact, I think it was a matter of using
>\eqno).  I told him that latex incorporates nearly all of plain tex, but I
>could never convince that the things that latex did well (sectioning,
>lists, etc) were real time savers.

Sorry for abusing this philosophical thread for proving my brilliance
in solving (La)TeX problems: Here is a completely LaTeX-compliant
version of Michaeal Barr's original problem (tested):

Equation~(\ref{eq:first}) is kind of an axiom:
$$\label{eq:first} 1=1$$

We derive equation~(\ref{eq:star}):
%% Following fails -- \renewcommand "to late" + bad
%% number for next equation -- to watch, comment in
%% and comment out below:
% $$% \renewcommand{\theequation}{*} \label{eq:star} 2=2 %$$
\newenvironment{nicetagequation}[1]
{\renewcommand*{\theequation}{#1}%
$$} {$$}
%% <- If you really use this, put it into the
%%    documentpreamble or into a project-related .sty
%% TODO -> packages
\begin{nicetagequation}{*}\label{eq:star}
2=2
\end{nicetagequation}

As a corollary, we get equation~(\ref{eq:third}):
$$\label{eq:third} 3=3$$

This replies to ...
At 17:45 25.08.06, William Adams wrote:

>First, $$...$$ is deprecated (see l2tabu on CTAN for more such).
>
>What you'd actually want to do for this is to define an environment
>which temporarily redefines the setting of the equation # as
>restoring the previous definition after the environment.

I had the same problem and used \eqno as well,
together with the deprecated $$...$$ -- I don't worry
-- Only here I have thought how to do it with LaTeX.
Indeed sometimes it is appropriate to label a displayed
formula in a way that the reader can easily remember
the content of that formula -- pages later. (When you write
a book, it may be essential to help the reader in finding
the equation ...)

Cheers,

Uwe.