March 2017

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GENERAL INFORMATION
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This is Nenofex ("NEgation NOrmal Form EXpansion"), an expansion-based QBF
solver which operates on negation normal form (NNF). A formula in NNF is
represented as a structurally restricted tree. Expansions of variables from
the two rightmost quantifier blocks are scheduled based on estimated expansion
costs. Further information can be found in our SAT'08 paper:

Florian Lonsing, Armin Biere: Nenofex: Expanding NNF for QBF
Solving. Proceedings of SAT 2008, volume 4996 of LNCS, Springer, 2008.

Version 1.1 is a maintenance release:
 - added simple API to enable library use
 - added support for most recent versions of PicoSAT solver

Apart from code maintenance, Nenofex is no longer actively developed. For bug
reports, please contact Florian Lonsing (see below).


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INSTALLATION
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Create a new directory DIR.

Download the latest source package of PicoSAT from http://fmv.jku.at/picosat/
copy it to DIR and unpack it. Installation should work with version 965 or any
later version.

In the directory of PicoSAT, call './configure -O -static' and then
'make'.

Make sure that the directory of PicoSAT is named 'picosat'. Rename it
if necessary.

Copy the source package of Nenofex to directory DIR and unpack it. The
directory tree should now look like 'DIR/picosat' and 'DIR/nenofex'. Call
'make' in the directory of Nenofex which produces optimized code without
assertions. The compilation process of Nenofex requires to have PicoSAT
compiled before in directory 'DIR/picosat/'.


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CONFIGURATION AND USAGE
-----------------------

Call './nenofex -h' to display usage information. Calling Nenofex without
command line parameters results in default behaviour.

The solver returns exit code 10 if the given instance was found satisfiable
and exit code 20 if the instance was found unsatisfiable. Any other exit code
indicates that the instance was not solved.

The subdirectory 'test' contains example programs that demonstrate the use of
the library of Nenofex.

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License
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DepQBF is free software released under GPLv3:

https://www.gnu.org/copyleft/gpl.html

See also the file COPYING.

Nenofex uses the SAT solver PicoSAT as an external library.

http://fmv.jku.at/picosat/

Please see the license of PicoSAT for further information.


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CONTACT
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For comments, questions, bug reports etc. related to Nenofex please contact
Florian Lonsing.

See also http://www.kr.tuwien.ac.at/staff/lonsing/