You have downloaded a collection of Magma programs and routines for
determining the Brauer group of a del Pezzo surface of degree 4 and the
obstruction to rational points that it produces.  You may wish to read the
documentation before using the program: if so, prepare and view the Plain
TeX file "doc.tex" (which should have been found accompanying this program)
in accordance with the demands of the your local computer system.

You are welcome to use, modify, or adapt this program for your own
mathematical work, but if you do so, the courtesy of an acknowledgment would
be greatly appreciated.  The program was written by Adam Logan, who asserts
the moral right to be recognized as its author.  For further details, see the
file "license".

Updated versions of this software may be released from time to time.
Check at the URL from which you downloaded the software in the first place.

Please note that the Magma system, unlike this software, is not free.
Instead a license may be obtained from the Computational Algebra Group at the
University of Sydney, Australia.

I would like to thank:

--the developers of Magma, for their wonderful software and quick bug fixes;
--Victor Flynn, for suggesting this problem;
--Martin Bright, Nils Bruin, and Victor Flynn (again), for useful suggestions
  during development;
--Mike Roth, for helping me to work out the quartic case;
--the mathematics department of the University of California, Berkeley,
  where some of the program was written;
--Anthony Varilly, for pointing some incompatibilities in the previous version
  of this software with Magma 2.13.

Adam Logan, Liverpool, UK
September 2004

and Waterloo, ON, Canada
a5logan@math.uwaterloo.ca
April 2007