X-Git-Url: https://git.distorted.org.uk/~mdw/mdwtools/blobdiff_plain/eafdddad07cf0a91ba07cbd9309a0a46e3bd00ac..0fb4766da19521ffc4b25ab564ce36e8c8df5f4b:/mdwmath.dtx

diff --git a/mdwmath.dtx b/mdwmath.dtx
index 92788ff..a9ff39f 100644
--- a/mdwmath.dtx
+++ b/mdwmath.dtx
@@ -1,6 +1,6 @@
 % \begin{meta-comment}
 %
-% $Id: mdwmath.dtx,v 1.2 2003/09/05 16:14:36 mdw Exp $
+% mdwmath.dtx
 %
 % Various nicer mathematical things
 %
@@ -38,7 +38,7 @@
 %<+oldeqnarray>                [1996/04/11 1.1 Old enhanced eqnarray]
 % \end{meta-comment}
 %
-% \CheckSum{729}
+% \CheckSum{740}
 %% \CharacterTable
 %%  {Upper-case    \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
 %%   Lower-case    \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
@@ -286,6 +286,43 @@
 % This also sets |\qedsymbol| if it's not set already.
 % \qed
 %
+% \subsection{Punctuation in displays}
+%
+% It's conventional to follow displayed equations with the necessary
+% punctuation for them to fit into the surrounding prose.  This isn't
+% universal: Ian Stewart says in the preface to the third edition of his
+% \emph{Galois Theory}:\footnote{^^A
+%   Chapman \& Hall/CRC Mathematics, 2004; ISBN 1-58488-393-6.} ^^A
+% \begin{quote}
+%   Along the way I made once change that may raise a few eyebrows.  I have
+%   spent much of my career telling students that written mathematics should
+%   have punctuation as well as symbols.  If a symbol or a formula would be
+%   followed by a comma if it were replaced by a word or phrase, then it
+%   should be followed by a comma; however strange the formula then looks.
+%
+%   I still think that punctuation is essential for formulas in the main body
+%   of the text.  If the formula is $t^2 + 1$, say, then it should have its
+%   terminating comma.  But I have come to the conclusion that eliminating
+%   visual junk from the printed page is more important than punctuatory
+%   pedantry, so that when the same formula is \emph{displayed}, for example
+%   \[ t^2 + 1 \]
+%   then it looks silly if the comma is included, like this,
+%   \[ t^2 + 1 \mpunct{,} \]
+%   and everything is much cleaner and less ambiguous without punctuation.
+%
+%   Purists will hate this, though many of them would not have noticed had I
+%   not pointed it out here.  Until recently, I would have agreed.  But I
+%   think it is time we accepted that the act of displaying a formula equips
+%   it with \emph{implicit} (invisible) punctuation.  This is the 21st
+%   century, and typography has moved on.
+% \end{quote}%
+%
+% \DescribeMacro\mpunct
+% I tended to agree with Prof.\ Stewart, even before I read his preface; but
+% now I'm not so sure, and it's clear that we're in the minority.  Therefore,
+% the command |\mpunct| sets its argument as text, a little distance from
+% the preceding mathematics.
+%
 % \begin{ignore}
 % There used to be an eqnarray here, but that's migrated its way into the
 % \package{mdwtab} package.  Maybe the original version, without dependency
@@ -318,7 +355,7 @@
 % The types provided (and it's easy-ish to add more) are:
 %
 % \def\ch{\char`}
-% \begin{description} \def\makelabel{\hskip\labelsep\normalfont\ttfamily}
+% \begin{description} \setdescriptionlabel{\normalfont\ttfamily#1}
 % \item [r] Right aligned equation
 % \item [c] Centre-aligned equation
 % \item [l] Left aligned equation
@@ -1081,6 +1118,26 @@
 % \end{macro}
 % \end{macro}
 %
+% \subsection{Punctuation in displays}
+%
+% \begin{macro}{\mpunct}
+%
+% This is actually a little more subtle than you'd expect.  If the
+% \package{amstext} package is loaded, or something else has defined the
+% |\text| command, then we should use that; otherwise, just drop a box in and
+% hope for the best.
+%
+%    \begin{macrocode}
+\def\mpunct#1{%
+  \,%
+  \ifx\text\@@undefined\hbox%
+  \else\expandafter\text\fi%
+    {#1}%
+}
+%    \end{macrocode}
+%
+%\end{macro}
+%
 % \begin{ignore}
 % The following is the original definition of the enhanced eqnarray
 % environment.  It's not supported, although if you can figure out how to