This directory contains the examples for the `chem' language written
in the book:

    Computing Science Technical Report No. 122
    CHEM - A Program for Typesetting Chemical Diagrams: User Manual
    by Jon L. Bentley, Lynn W. Jelinski, Brian W. Kernighan

The book is available in the internet at
<http://cm.bell-labs.com/cm/cs/cstr/122.ps.gz>.

Many of the examples had to be fixed.  Unfortunately, the `chem' akw
version does not run on many of these programs.  But the Perl version
of `chem' works on all examples.

Most examples do not use the modern chemical display.  They have C
atoms added, whereas the modern method omits all C atoms and their
directly appended H atoms.

The examples are named and sorted by the chapter where they are found
in the book.  For example, the file `ch4c_colon.chem' means a `chem'
example in chapter 4; according to `c', it is the third example in
this chapter; the name `colon' is used to describe the context of the
example.

You can view the graphical display of the examples by calling

    groffer <file>

`groffer' calls `chem' automatically.

If you want to transform example files to a different format use the
`roff2*' programs:

`roff2dvi' prints dvi format to standard output,
`roff2html' generates html output,
`roff2pdf' outputs pdf mode,
`roff2ps' produces PostScript output,
`roff2text' generates text output in the groff device `latin1',
`roff2x' prints the output  in  the  groff  device  X  that  is
         suitable  for programs  like `gxditview' or `xditview'.

To get a suitable `groff' output run

    chem <file> | groff -p ...


####### 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) version 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.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.

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


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