# Integral kerning

• To: math-font-discuss@cogs.susx.ac.uk
• Subject: Integral kerning
• From: Matthias Clasen <mclasen@sun2.mathematik.uni-freiburg.de>
• Date: Mon, 29 Sep 1997 10:15:53 +0200 (MET DST)

One of the ideas in Justin Zieglers work was to kern the integrals with
themselves to make it possible to write \int\int instead of \iint. Last
weekend I have discovered that this is impossible (at least for the
textstyle bigops), since Knuth says on p318 of the mfbook:

Notice that a <label> can appear in a ligtable, charlist or extensible
command. These appearances are mutually exclusive: No code may be used
more than once as a label. Thus, for example, a characer with a
ligature/kerning program cannot also be extensible, nor can it be in a
charlist (except as the final item).

After this discovery, I have removed the experimental kerning from the
MX1-fonts (now even understanding the errors which vptovf gave me).

Regards, Matthias

--
Matthias Clasen
Albert-Ludwigs-Universitaet Freiburg
Institut für Mathematische Logik
79104 Freiburg, Germany.   Tel.: +49 (0) 761-203-5606