`chem' is a `roff' language to generate chemical structure diagrams.
`@g@chem' is a `groff' preprocessor that produces output suitable for
the `@g@pic' preprocessor.

The original version of `chem' is an `awk' script written by Brian
Kernighan <http://cm.bell-labs.com/cm/cs/who/bwk/index.html>.  The
source files of the `awk' version of `chem' are available at
<http://cm.bell-labs.com/netlib/typesetting/chem.gz>.

This project is a rewrite of `chem' in Perl for the GNU `roff' project
`groff'.  It was written under Perl v5.8.8, but at least Perl v5.6 is
needed to run the Perl version of `chem'.

In comparison to the original `awk' version of `chem', the Perl
version does the following changements:
- the options -h, --help, -v, --version to output usage and version
information are added.
- remove some functions `inline', `shiftfields', and `set' and some
variables that are used only once.

The subdirectory `examples/' contains example files for chem.  They
are written in the `chem' language.  The file names end with .chem.


####### License

Copyright (C) 2006-2014 Free Software Foundation, Inc.
Written by Bernd Warken <groff-bernd.warken-72@web.de>.

This file is part of `chem', which is part of `groff'.

`groff' is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License (GPL) vbersion 2 as
published by the Free Software Foundation.

`groff' is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

The GPL2 license text is available in the internet at
<http://www.gnu.org/licenses/gpl-2.0.html>.


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