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<p>I am going to assume that you want the \widering from </p>
<p>yhmath.sty.</p>
<p><br>
</p>
<p>This was a bit tough, mostly because there is a bug </p>
<p>in its definition in yhmath.sty. But here goes:</p>
<p><br>
\input eplain</p>
<p>% load the yh font for \wideparen<br>
\font\yhten =yhcmex10<br>
\font\yhseven=yhcmex10 at 7pt<br>
\font\yhfive =yhcmex10 at 5pt</p>
<p>% set up the math family for using it<br>
\newfam\yhfam<br>
\textfont\yhfam\yhten<br>
\scriptfont\yhfam\yhseven<br>
\scriptscriptfont\yhfam\yhfive</p>
<p>\def\yhex{\fam\yhfam}</p>
<p>% determine the hex digit for this new math family <br>
\edef\yhhex{\ifcase\yhfam 0\or 1\or 2\or 3\or 4\or 5\or 6\or 7\or 8\or<br>
9\or A\or B\or C\or D\or E\or F\fi}<br>
<br>
\def\wideparen{\mathaccent"0\yhhex F3}<br>
\def\ring{\mathaccent"17}<br>
\def\widering#1{\ring{\wideparen{#1}}}<br>
Test: $\widering{ABC}$.<br>
<br>
\bye</p>
<p><br>
</p>
<p>Oddly, cmr contains the ring accent, but plain TeX doesn't</p>
<p>have a command to access it directly (just \aa for the accent </p>
<p>over an "a").</p>
<p><br>
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<p>Dan<br>
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<div style="font-family:Tahoma; font-size:13px"><font size="3" face="Courier New">Daniel H. Luecking [luecking@uark.edu]
<br>
Department of Mathematical Sciences<br>
1 University of Arkansas<br>
Fayetteville, AR, USA 72701-1201</font><br>
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<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" color="#000000" face="Calibri, sans-serif"><b>From:</b> tex-eplain <tex-eplain-bounces@tug.org> on behalf of Gérald Tenenbaum <gerald.ten@free.fr><br>
<b>Sent:</b> Tuesday, November 15, 2016 5:10 PM<br>
<b>To:</b> tex-eplain@tug.org<br>
<b>Subject:</b> [tex-eplain] widering</font>
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<div>Hello,</div>
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<div>How can one include the LaTeX command \widering into Eplain?</div>
<div>Many thanks for help.</div>
<div>Regards,</div>
<div><br>
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<div>Gérald</div>
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