Message-Id: <199402282032.AA01633@mail.cs.tu-berlin.de>
Reply-To: Mailing list for the LaTeX3 project <LATEX-L@DHDURZ1.BITNET>
Date:         Mon, 28 Feb 1994 17:33:57 +0100
From: "Rik Huygen k297 tel. 4799" <rik@sron.rug.nl>
Sender: Mailing list for the LaTeX3 project <LATEX-L@DHDURZ1.BITNET>
To: Multiple recipients of list LATEX-L <LATEX-L@DHDURZ1.BITNET>
Subject:      (La)TeX conditional compilation
Status: R

Hi LaTeX specialists,

I would like to present you a small (?) problem I have with conditional
TeX-ing. Let me state the problem properly:

I have a program documentation which contains information for moderate
and for expert users, something like the TeX manual with the dangerous
bend.  I now would like to include/exclude the expert information
depending on the type of manual.  But I would like the expert info in a
begin/end environment: \begin{Expert} .... \end{Expert} (see example below).

If I use plain TeX everything works fine.  If I want to use an
environment instead of the \ifSomeCondition ....  \fi construction fails
on the `false'.  I get the following message:

! Incomplete \iffalse; ...

Apparently, TeX wants to read the false part of the \if construction
too. I tried all kinds of tricks, using \relax, \bgroup \egroup
constructs but until now nothing worked properly.

Is there someone who has solved this problem previously?

I will be very happy if someone can solve this one for me.

Rik.

------------------------------ EXAMPLE ----------------------------

\documentstyle{article}

\newif\ifSomeCondition

\newenvironment{Expert}{\ifSomeCondition}{\fi}

\begin{document}

\SomeConditiontrue

\ifSomeCondition
   If you see this, the Condition is true!
\else
   If you see this, the Condition is false!
\fi

\SomeConditionfalse

\begin{Expert}
This is only for expert users, i.e., if SomeCondition is true!
\end{Expert}

\end{document}


+----------------------------------------------------------------------------+
|  Dr. Rik Huygen        | SRON Space Research Laboratory                    |
|                        | P.O. Box 800, 9700 AV Groningen, The Netherlands  |
|  rik@sron.rug.nl       | phone: +31 (0)50 634799  +31 (0)50 123662 (home)  |
|                        | FAX  : +31 (0)50 634033                           |
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