# Bottom margin vs. descenders question

Axel E. Retif axel.retif at gmail.com
Sun Jul 5 20:01:15 CEST 2020

On 7/5/20 11:52 AM, Doug McKenna wrote:

> Enclosed is a screenshot of what I have tried to output in my program.
> The red lines have been superimposed onto the PDF to show where the
> margin bounds are.  This seems a perfect example of what has just been
> discussed: a math formula with large delimiters on the bottom line of
> the page that descend quite a bit into the margin area in order to
> maintain the baseline of the bottom line on every page at the same
> vertical position.  It is typeset properly, even though it breaches the
> margin.  I believe this was typeset with TeX/LaTeX.

If the red line marks the height of the page *in multiples* of the
baselineskip, then indeed the delimiters are protruding *a lot*. In that
case the descenders of p's and q's of the confronted page would coincide
with the parentheses of the formula number (2).

But maybe (La)TeX is balancing the baseline of the formula and the
protrusion of the delimiters; in this case, the baseline of the formula
would be higher than the baseline of text in the confronted page. One
has to see the confronted page or measure any other page that ends with
text to see what's happening.

Be it as it may, those delimiters of the formula are larger than
desirable. In the TeXbook, p. 149, Knuth advises to use \bigl(, \Bigl(,
\biggl(, etc., and corresponding \biggr), etc., instead of \left( and
\right).

Best

Axel