# [OS X TeX] OT: spacing after operator in math

Frank STENGEL fstengel at mac.com
Fri Dec 22 14:04:04 EST 2006

```Le 22 déc. 06 à 19:26, Frank STENGEL quite hastily wrote :

>
> It seems to be hard-coded in TeX.

Not completely.

> There is a table explaining what kind of space is added when in
> chapter 18 of the TeXBook (p170 in my copy). The TeX primitives
> \mathop, \mathrel, \mathopen, \mathclose etc. will adjust spacing
> around their arguments.

This is what is hard-coded. However in appendix G. rule 20 (p446 in
my copy), DEK says that the spaces used are those given by the three
registers \thinmuskip, \medmuskip and thickmuskip (corresponding to
the 1, 2 and 3 entries in the aforementionned table. consider the
following ugly code:

\$\$a+b\$\$

\medmuskip=50mu

\$\$a+b\$\$

In the second, the spacing around the + will be quite large.

In the hope I wasn't too obscure

--
Frank STENGEL (fstengel<at>mac.com)