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<div class="moz-cite-prefix">I think, David, that Doug was asking
about typographical rules rather than TeX practice (for which I
will need to consult Hart, Brighurst, <i>et al.</i> before
attempting a proper reply) but I am now wondering whether there
are pathological cases where a TeX descender might protrude into
the lower margin. The case I have in mind is as follows. The
page consists of normal text with the sole exception of the
penultimate line; on that line, descenders are grossly
exaggerated. Assuming that \lineskip (etc) are set such that the
penultimate and the final line occupy their normal location in the
galley (i.e., are not forced apart by the excessive descender
depth), might the penultimate line's descenders intrude into the
lower margin, even though the descenders of the final line will
not ? The answer would appear to be "yes" —<br>
<br>
<blockquote type="cite">% !TeX Program=XeTeX
<p style="-qt-paragraph-type:empty; margin-top:0px;
margin-bottom:0px; margin-left:0px; margin-right:0px;
-qt-block-indent:0; text-indent:0px; line-height:100%;"><br>
</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">\parskip = 0 pt </p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">\parindent = 0 pt</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">\obeylines</p>
<p style="-qt-paragraph-type:empty; margin-top:0px;
margin-bottom:0px; margin-left:0px; margin-right:0px;
-qt-block-indent:0; text-indent:0px; line-height:100%;"><br>
</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">\font \gfont = cmr10 scaled 5000</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">\def \good {\lower 3,5 ex \hbox {\gfont
g}ood }</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">\lineskip = 0 pt</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">\lineskiplimit = -\maxdimen</p>
<p style="-qt-paragraph-type:empty; margin-top:0px;
margin-bottom:0px; margin-left:0px; margin-right:0px;
-qt-block-indent:0; text-indent:0px; line-height:100%;"><br>
</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">\topglue 0 pt</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">\vfill</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">The Leith police dismisseth us, for we
sufficeth them.</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">The quick brown fox jumps right over the
lazy dog's back.</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">Now is the time for all \good men to come
to the aid of the party.</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">Here endeth the first lesson.</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">\eject</p>
<p style="-qt-paragraph-type:empty; margin-top:0px;
margin-bottom:0px; margin-left:0px; margin-right:0px;
-qt-block-indent:0; text-indent:0px; line-height:100%;"><br>
</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px;
margin-right:0px; -qt-block-indent:0; text-indent:0px;
line-height:100%;">\end</p>
</blockquote>
<br>
Philip Taylor<br>
--------<br>
David Carlisle wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAEW6iOgZHfEwHZd0MA3k2fginT1dc2YpnnC5qgOh2OhrZwEt7A@mail.gmail.com">
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<div dir="ltr">
<div>tex has a parameter \maxdepth (for the main page) (and
\boxmaxdepth for other boxes being constructed) that sets how
far you are allowed to go below. If the descenders on the last
row are bigger than \maxdepth then the row doesn't fit and the
page breaks earlier (or shrinks more or whatever) latex and
plain set \maxdepth to 4pt by default so normal letter
descenders don't affect the position of the last row.</div>
<div><br>
</div>
<div>David<br>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Thu, 25 Jun 2020 at 05:24,
Doug McKenna <<a href="mailto:doug@mathemaesthetics.com"
moz-do-not-send="true">doug@mathemaesthetics.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Dear
typesetting cogniscenti,<br>
<br>
In "official typesetting rules" (TeX or otherwise) are
descenders supposed to be completely above the bottom margin
bounds of a page? Or is just the baseline of the bottom line
of a full page supposed to conform to the margin bounds?<br>
<br>
Doug McKenna<br>
Mathemaesthetics, Inc.<br>
</blockquote>
</div>
</blockquote>
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