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Hello Juan,<br class="">
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<div class="">On 31 Jan 2020, at 2:53 pm, juan tolosa via MacOSX-TeX <<a href="mailto:macosx-tex@email.esm.psu.edu" class="">macosx-tex@email.esm.psu.edu</a>> wrote:</div>
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<div class="">I wanted to create a “double arrow overline” in plain TeX; I created the macro \overleftrightarrow by imitating what is done in the TeXbook in creating “overleftarrow” and “overrightarrow” After some tweaking, I got it to work. But here is the
strange thing: by coincidence, I had the command “\input\miniltx.tex” at the beginning of the file, which I use to be able to draw pictures using the “graphicx” package. The problem is, if I remove this command, then the definition doesn’t work, the typesetter
complains about the command “\m@th”<br class="">
I was blindly following the definitions in the TeXbook, my knowledge of the fine points in TeX is very (very!) limited. Still, I am baffled, since Knuth’s book deals with plain TeX, not with LaTeX.<br class="">
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Can anyone illuminate me and let me know why is “miniltx” required for this definition to work?<br class="">
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<div>It isn’t.</div>
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<div>You just need to change the \catcode of @ while definitions using it are being made:</div>
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Thanks<br class="">
Juan<br class="">
<br class="">
Below is a sample file<br class="">
<br class="">
%<br class="">
\input miniltx.tex <br class="">
% \RequirePackage{graphicx} <br class="">
<br class="">
%<br class="">
%%%%%%%%%%%%%%%%%%<br class="">
%<br class="">
% DEFINE "over left right arrow". INSPIRATION:<br class="">
%. TeX book, definition of \overleftarrow on p. 359<br class="">
%. plus definitions of \leftarrowfill and \rightarrowfill on p. 357<br class="">
% First need "left right arrow fill” defined<br class="">
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<div>\catcode`\@ 11 %%% <<<< make @ into a letter</div>
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<div class="">\def\leftrightarrowfill{$\m@th \mathord\leftarrow \mkern-6mu<br class="">
\cleaders\hbox{$\mkern-2mu \mathord- \mkern-2mu$}\hfill<br class="">
\mkern -6mu \mathord \rightarrow$}<br class="">
%<br class="">
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<div>\catcode`\@ 12 %%% <<<< revert @ to being a punctuation character</div>
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<div class="">\def\overleftrightarrow#1{\vbox{\ialign{##\crcr<br class="">
\leftrightarrowfill\crcr\noalign{\kern-1pt\nointerlineskip}<br class="">
$\hfil\displaystyle{#1}\hfil$\crcr}}}<br class="">
%<br class="">
%________________________________________________________________<br class="">
<br class="">
Any two distinct points $A$ and $B$ determine a unique line $\overleftrightarrow{AB}$.
<br class="">
<br class="">
\bye<br class="">
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<div>Hope this helps.</div>
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<div><span class="Apple-tab-span" style="white-space:pre"></span>Ross</div>
<br class="">
<div class=""><br class="">
Dr Ross Moore<br class="">
Department of Mathematics and Statistics
<div class="">12 Wally’s Walk, Level 7, Room 734<br class="">
Macquarie University, NSW 2109, Australia<br class="">
T: +61 2 9850 8955 | F: +61 2 9850 8114<br class="">
M:+61 407 288 255 | E: <a href="mailto:ross.moore@mq.edu.au" class="">ross.moore@mq.edu.au</a><br class="">
<a href="http://www.maths.mq.edu.au" class="">http://www.maths.mq.edu.au</a><span style="font-size: 12px; line-height: normal;"><a href="http://mq.edu.au/" target="_blank" style="font-size: 12px; line-height: normal;" class=""><span><br class="Apple-interchange-newline" style="caret-color: rgb(0, 105, 217); color: rgb(0, 105, 217); font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-family: Arial, sans-serif; orphans: 2; widows: 2;">
<span style="caret-color: rgb(0, 105, 217); color: rgb(0, 105, 217); font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-family: Arial, sans-serif; orphans: 2; widows: 2;"><span><span><span><span><img apple-inline="yes" id="F52E62E5-85D8-4861-9480-E3B8C8ADC25D" src="cid:image001.png@01D030BE.D37A46F0" class=""></span><br style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none;" class="">
<span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class="">CRICOS
Provider Number 00002J. Think before you</span><span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class=""> </span><span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class="">print. </span><br style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none;" class="">
<span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class="">Please
consider the environment before printing this</span><span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class=""> </span><span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class="">email.</span><br style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none;" class="">
<br style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none;" class="">
<span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class="">This
message is intended for the addressee named</span><span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class=""> </span><span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class="">and
may </span><br style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none;" class="">
<span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class="">contain
confidential information. If you are not the</span><span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class=""> </span><span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class="">intended </span><br style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none;" class="">
<span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class="">recipient,
please delete it and notify the sender. Views</span><span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class=""> </span><span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class="">expressed </span><br style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none;" class="">
<span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class="">in
this message are those of the individual sender, and</span><span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class=""> </span><span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class="">are
not </span><br style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none;" class="">
<span style="font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; text-decoration: none; float: none; display: inline !important;" class="">necessarily
the views of Macquarie University.</span> </span></span></span></span></span></a></span></div>
<a href="http://mq.edu.au/" target="_blank" style="font-size: 12px; line-height: normal;" class=""></a></div>
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