# [texhax] Why is \rm deprecated?

Ulrike Fischer news3 at nililand.de
Tue Aug 18 10:37:39 CEST 2015

Am Mon, 17 Aug 2015 19:49:36 -0400 schrieb Michael Barr:

> The fact that it is is clear.  I would like to know why it is deprecated.

It is "deprecated" because it has been removed from the kernel.

\rm was in LaTeX2.09 one of the "core" font switching command but is
not in LaTeX2e as there the (much better)new font selection sheme
(nfss) was introduced with its "additive" commands which doesn't
change to fixed fonts but allows the changes of attributes. \rm
didn't fit in the new set of core font commands.

So if you want to use it -- and you have every right to use special
commands, as you can use "\redfont" oder "\decofont" -- you can't
rely on the kernel. You will have to use a class or a package that
provides the command or define it yourself.

> In a similar vein, why is it recommended to use $$...$$ for equations

It isn't. You can use $...$ if you want (unless your editor can
handle the highlighting of $$...$$ better).

> and $...$ for displays?

Because you get better spacing and options like fleqn don't work
with $$...$$. See also
http://www.tex.ac.uk/FAQ-dolldoll.html

> TeX is tool, not a religion.  Why are people trying to enforce conformity?  Foolish hobgoblins.

Currently the only one with some religious indignation here is you.
Why are you fighting so hard for the right to use  or \rm? Simply
do it if you think you know what you are doing.

> Someone at AMS explained to me that \over
> was inconsistent, being the only place in all of TeX (leaving
> aside related things such as \overwi! thdelimiter) that used
> infix notation.  So what?  Somewhere I read or heard Knuth say
> that when he lectured to mathematicians on an early version of
> TeX, they actually cheered when he described \over.

Read technote.pdf from the amsmath package if you want to understand
the problems with \over and friends.

> As far as I am concerned, undefining a kernel function can be
> described only as vandalism.

An religion again. TeX and LaTeX aren't faultless. There is place
for improvement. As a special command \rm is ok, as core font
command it was *bad*, and it was the correct decision to remove it
from the kernel.

--
Ulrike Fischer
http://www.troubleshooting-tex.de/