# [texhax] Cases for italic correction

Philip TAYLOR P.Taylor at rhul.ac.uk
Fri Jul 20 15:00:24 CEST 2012


Michael Barr wrote:

> The following illustrated another use for italic correction:
>
> \documentclass{article}
>
> \begin{document}
> $d^3=d\/^3=d{}^3$
>
> \end{document}
>
> I am sorry, but you have really have to see the output to appreciate the
> difference.

I don't think that is a very helpful remark when addressed to
someone who is blind, Michael.  If there is something tangible that
can be seen, then that same something can be described in words,
as I tried to do when the "row of bricks" analogy arose.

> It illustrates a real defect in tex.  The mit version of d
> leans well outside the "bounding box" in a way that almost other letter
> does (I think f might be another) and when you add a superscript, it
> crashes into that ascender.  I wrote a book that had several hundred
> d^n, where n was either a number or a letter.  These were face
> operators, for which the d was the only letter ever used.  I used a
> macro called \dee that added a little extra space, but an italic
> correction would have worked fine.  I didn't realize until I tested it
> just now that a pair of braces would also have worked.

I have processed your example using PdfLaTeX, and examined the output
at the greatest magnification of which Adobe Acrobat 7 Professional
is capable.  I can detect not one iota of difference in the three
instances of d^3; what am I missing ?

** Phil.