[texhax] le vs leq and \ZZ vs \Z

Lars Madsen daleif at imf.au.dk
Mon May 25 20:52:44 CEST 2009

Konstantin Ziegler wrote:
> Dear list,
>
> 1. I'm using LaTeX for quite some time now and have always wondered why
> there are two possibilities to typeset the "less or equal than" symbol.
>
> Why are there two commands "le" and "leq" to typeset the same symbol?
> Is it just for historical reasons or is there a "proper" way to do it?
>
> 2. Along the lines of "doing things properly":  There are certainly lots
> of people out there who use on of the two following macros
>
> \DeclareMathOperator{\ZZ}{\mathbb{Z}}
> \DeclareMathOperator{\Z}{\mathbb{Z}}
>
> to typeset integers.  While the second one is shorter, a friend of mine
> warned by about one-letter-macros labelling them "bad style".  Do you agree?
>

both may be out of code readability, if you do not know what \le looks
like A \le B doesn't make much sence, but because a lot of symbols
containing eq means 'something equals' most users will guess that \leq
means less than.

The same goes for the short names for sets etc., I agree it is bad
style, because one cannot understand the code unless you have read the
preamble. I recommend my users to use naming such that the code actually
makes sense without looking at the output.

For example in topology we often use the combination of = and ~ to
indicate an isomorphism, but reading M \cong N does not make much sense,
here I recommend to users that they define a new macro \isomorph equal
to \cong and use this throughout. Some journal editors does not like
this, but as long as it is consistent then it is easy to change.

Some users may use \Z for one thing, but their colleague use it for
something different, which make cooperation difficult. Another problem
with the very short names (one letter) if that they are often used for
accents, which again
confuse users.

/daleif