[texhax] le vs leq and \ZZ vs \Z
bnb at ams.org
Mon May 25 21:08:30 CEST 2009
On Mon, 25 May 2009, Uwe Lueck wrote:
Barbara Beeton <bnb at ams.org> schrieb am 25.05.2009 20:39:00:
> 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?
> the choice of which to use is usually
> what is known as "house style"; in
> most situations, the single or double
> horizontal rule doesn't change the
> meaning, but some publishers prefer
> the single, and some the double rule.
> (some mathematicians also have strong
> preferences.) so you could say it's
No, Barbara, \le and \leq are synonyms for the same symbol, see TeXbook p. 436/438, there:
"Some symbols have alternate names that are so commonly used that plain TeX provides two or more equivalent control sequences."
\leqq from the amssymb package has a double horizontal rule.
correct. thanks, uwe.
in the case of \le and \leq, both are
defined in plain.tex; the basic one is
\leq, and then \let\le=\leq .
so this was don knuth's decision.
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