Re: Re: \nbsp usage

[Nick Dokos <nicholas.dokos@hp.com>]

Bernt Hansen <bernt@norang.ca> wrote:

> Erik Butz <erik.butz@googlemail.com> writes:
> 
> > Hi all,
> >
> > I have a somewhat stupid problem, but didn't find a solution in the
> > manual or the list archive.
> > I want to use the \nbsp macro to generate a '~' symbol for Latex, but
> > I don't seem to get it to work correctly in my case.
> > I want to write 200~m=C2=B2
> >
> > If I do: 200\nbspm^2
> > it gets exported as: 200\nbspm$^2$,  so the symbol is not recognized.
> >
> > If I do: 200\nbsp m^2
> > it gets exported as 198~ m$^2$, so in addition to the nbsp there is
> > another space at which a linebreak can occur
> >
> > trying: 200\nbsp{}m^2 in analogy to other commands
> > I get: 200~\{\}m$^2$, so the parentheses are not recognized as
> > belonging to the command.
> >
> > I am using the latest org version (just did a git pull and checked
> > that the behavior is still there) with emacs 23.1.1
> >
> > Any hints appreciated.
> 
> Hi Erik,
> 
> This seems to work for me:
> 
> ,----[ sample org file ]
> | * nbsp
> | If I do: one two three four five six seven eight nine ten eleven twelve 2=
> 00\nbsp m^2 it gets exported
> `----
> 
> this exports as=20
> 
> ,----[ latex output ]
> | ...
> | \label{sec-1}
> |=20
> | If I do: one two three four five six seven eight nine ten eleven twelve 2=
> 00~ m\^{}2 it gets exported
> | \end{document}
> `----
> 
> and when I look at that as a PDF it doesn't break between the 200 and
> m^2.  I tried adding x and xx before the 200 and it pushes the entire
> thing to the next line.  I can't make it break on a line so 200 is at
> the end of one line and m^2 is on the following line.
> 
> Does this work for you?
> 

Bernt,

I suspect that you cannot decide the question with a simple experiment
like this, but I have no counterexample to offer.

However, Knuth warns explicitly (p.91 of my version of the TeXbook,
paperback 19th printing, Oct. 1990) that "...you shouldn't leave any blanks
next to the ~, since they will count as additional spaces."

It may well be that TeX's line-breaking algorithm does the right thing in
the example, but when push comes to shove in a *really* complicated situation,
it might be forced to choose the space after the tilde to break the line at.

Regards,
Nick