When I look at different uses of glue in spacing, I see both \@minus
and minus
.
What's the difference between \@minus and minus?
TeX - LaTeX Stack Exchange is a question and answer site for users of TeX, LaTeX, ConTeXt, and related typesetting systems. It only takes a minute to sign up.
Sign up to join this communityWhen I look at different uses of glue in spacing, I see both \@minus
and minus
.
What's the difference between \@minus and minus?
You can see some information in my answer to \raggedyleft in memoir?
The expansions of \@minus
and \@plus
are, respectively, minus
and plus
. But \@minus
counts as one token in the replacement text of a macro, whereas minus
counts as five.
Now, \@plus
appears 16 times in latex.ltx
(one is the definition), 15 times in article.cls
and 36 times in size10.clo
, which makes for a saving of (15+15+36)*(4–1) = 198 tokens on every standard document in the article
class. This might appear ridiculous nowadays, but, when LaTeX2e was released, memory was really scarce and even such savings were worthwhile. There are several other token saving tricks such as \z@
, \p@
, \hb@xt@
and so on, which (on some TeX distributions) made the difference between being able to run LaTeX or not.
\def\@minus{minus}
\@minus
just saved a few things in Texs memory (or something like that, there is a word for what was saved, but I've forgotten it)