Re: [Axiom-developer] hyperlinked algebra

[Ralf Hemmecke]

Bill Page wrote:
> On December 15, 2005 10:35 AM Tim Daly (root) wrote:
> > in tex if you want a 2 character command (say \n) but no 
> > space you write:
> >
> > foo\n{}bar ==> foo\nbar
> >
> > the {} tells tex that \n has ended

Right.

> and has no argument.

I tend to say that is wrong. The definition of \n says whether \n takes 
an argument at all. {} is just an empty group which could have some 
influence though on the hyphenation algorithm, IIRC.

> I believe that
>
> foo\n bar  <==>  foo\n{}bar
>
> are identical. No?

They don't look identical, but they do the same thing as long as you 
haven't redefined the meaning of { and } and the meaning of the space 
character. They would not be identical, if there where the following 
definition around.

As a proof of concept look at what the following code gives.
Note especially how the space in "backslash n" gets typeset in the .dvi.

Happy TeXing... ;-)
Ralf

\documentclass{article}
\expandafter\def\csname n bar\endcsname{BAR}
\catcode`\ =11%consider space as belonging to the category "letter"
\def\n{(backslash n)}
\begin{document}
\fbox{foo\n bar}
\fbox{foo\n{}bar}
\end{document}