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<div class="moz-cite-prefix">On 27/08/2023 10:41, Gérald Tenenbaum
wrote:<br>
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<blockquote type="cite"
cite="mid:a33ffb81-faff-076e-ff07-7d9b702c85c5@univ-lorraine.fr">
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<div style="font-size: 12px;font-family: Lucida Sans;">Thanks.<br>
Yes it suffices, but I also need these boldface letters in
subscripts.<br>
I am puzzled by the necessity of using \hbox. Can't one design a
setting working like \bf or \it ?</div>
</blockquote>
<p>Unfortunately, not easily — see <i>The TeXbook,</i>, p.~153 :</p>
<p>
<blockquote type="cite">During the time that a maths formula is
being read, TeX remembers each symbol<br>
as being “character position so-and-so in family number
such-and-such” but it does<br>
not take note of what fonts are actually in the families until
reaching the end of the formula.<br>
<br>
Thus, if you have loaded a font called \Helvetica that contains
Swiss-style numerals, and if<br>
you say something like <font size="+1"><tt>$\textfont 0 =
\tenrm 9 \textfont 0 = \Helvetica 9$</tt></font><br>
you will get two 9s in font \Helvetica, assuming that TeX has
been set up to take 9s from<br>
family 0. <br>
<br>
The reason is that \textfont 0 is \Helvetica at the end of the
formula, and that’s<br>
when it counts. On the other hand, if you say <font size="+1"><tt>$\textfont
0 = \tenrm 9 \hbox {$9\textfont 0 = \Helvetica$}$, </tt></font>the
first 9 will be from \tenrm and the second from \Helvetica,
because the formula in the<br>
hbox will be typeset before it is incorporated into the
surrounding formula.</blockquote>
-- <br>
<i>Philip Taylor</i><br>
<br>
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