Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!uunet!mcsun!ukc!cam-eng!pi
From: pi@eng.cam.ac.uk (Pablo Iglesias)
Newsgroups: comp.text.tex
Subject: Re. Getting rid of minus signs
Message-ID: <24936@rasp.eng.cam.ac.uk>
Date: 27 Mar 91 23:41:57 GMT
Sender: news@eng.cam.ac.uk
Lines: 38

I wrote
> I want to create a command in LaTeX which would do the following:
>
> \negate{A} would give me -A.
> \negate{-A} would give me A.


I want to thank the several people who answered my query.  The
following, due to David Carlisle was the first solution that
I got, and it did exactly what I wanted.  I include it in case
anyone else wants to know.


-Pablo
--------------------------------------------------
% Document Type: LaTeX
% Master File: xx.tex
%
\documentstyle{article}

\makeatletter
\def\neg@te{\@ifnextchar-{\@gobble}{-}}
\def\negate#1{\neg@te#1}
\makeatother

\begin{document}

$\negate{-7}$

$\negate{88}$

$\negate{99} + \negate{-99} = 0$
\end{document}
--
Pablo Iglesias                  Phone : +44 223 332813           
Department of Engineering       Fax   : +44 223 332662           
Cambridge University            email :  pi@eng.cam.ac.uk        
Cambridge, CB2 1RD, UK