PySAT is being developed with the rolling release model, which means we do not deliver major releases from time to time. Instead, many small (sometimes tiny) and frequent updates are provided. As a result, upgrading your installation of the toolkit every now and then to keep it up-to-date is good idea.

11.04.2024 (1.8.dev10)

  • Fixed a bug in simplified() method for XOr terms.

07.04.2024 (1.8.dev9)

  • Fixed implementation of propagate() for CaDiCaL 1.9.5.

05.04.2024 (1.8.dev8)

  • Added support for CaDiCaL 1.9.5 with linear engine in example scripts.

31.03.2024 (1.8.dev7)

  • Fixed a bug in formula key flattening.
  • Added support for empty conjunctions and disjunctions representing PYSAT_TRUE and PYSAT_FALSE respectively.

27.03.2024 (1.8.dev6)

  • A few minor issues in the toolkit setup.

20.03.2024 (1.8.dev5)

  • Fixed a few issues in formula simplification.

17.03.2024 (1.8.dev4)

  • Fixed a bug in the PB encoder.
  • Added support for CaDiCaL 1.9.5.
  • Added module engines supporting external propagators.

29.02.2024 (1.8.dev3)

  • Minor corrections.

29.02.2024 (1.8.dev2)

  • Fixed a bug/typo in implication clausification.
  • Added checks for the number of arguments in And, Or, Equals, and XOR constraints.

25.02.2024 (1.8.dev1)

  • Changed versioning scheme.
  • Added functionality to manipulate arbitrary Boolean formulas.

20.02.2024 (0.1.8.dev17)

  • Fixed a minor bug once in a while manifesting itself in the solvers' destructors.

18.02.2024 (0.1.8.dev16)

  • Added an option in CNF constructor to copy clauses by reference instead of deep-copying them (if the CNF is constructed from clauses).

07.02.2024 (0.1.8.dev15)

  • Corrected polarities of core literals if extracted from CryptoMiniSat.

31.01.2024 (0.1.8.dev14)

  • Added a standard Python destructor for each solver so that the garbage collector manages to destroy the objects, if this is not done by the user explicitly.

09.01.2024 (0.1.8.dev13)

  • Fixed the issue of a missing variable in CaDiCaL’s unsatisfiable core handling after a limited SAT call.

28.11.2023 (0.1.8.dev12)

  • Added (rudimentary) support of CryptoMiniSat5 by means of the pycryptosat package’s interface.

24.11.2023 (0.1.8.dev11)

  • Added another external tool (UniGen3) to the module pysat.allies.

13.10.2023 (0.1.8.dev10)

  • Added assumption-based propagation functionality to CaDiCaL 1.5.3 (thanks to Zi Li Tan).

12.07.2023 (0.1.8.dev9)

  • Updated proof logging in Glucose 4.2.1 (thanks to Marco Marino).

12.07.2023 (0.1.8.dev8)

  • Added Glucose 4.2.1 (thanks to Marco Marino).

09.06.2023 (0.1.8.dev7)

  • Minor fix in RC2 making the new version backward compatible with the old API.

04.06.2023 (0.1.8.dev6)

  • Added parameter setting for CaDiCaL 153.
  • Added an interface for preferred polarity setting in CaDiCaL 153.
  • Added CaDiCaL 153 as a possible oracle to Hitman.
  • Added phase switching in Hitman when pure SAT-based enumeration is used.
  • Added an option to use pure SAT-based hitting set enumeration in OptUx.

03.06.2023 (0.1.8.dev5)

  • Exposed cadical’s limited solving capability.
  • Added pure SAT-based minimal hitting set enumeration through the use of phase preferences.

25.05.2023 (0.1.8.dev4)

  • Another attempt to fix the bug in RC2 related to stratification and weight splitting (thanks to Bart Bogaerts, Andy Oertel, Jeremias Berg, Jakob Nordström, and Dieter Vandesande).
  • Multiple slight amendments in the formula API (thanks to Rex Yuan).

21.04.2023 (0.1.8.dev3)

  • Added a new module called pysat.allies, which is meant to contain external tools callable from PySAT. The first tool added is ApproxMCv4.

19.03.2023 (0.1.8.dev2)

  • Fixed a subtle bug in RC2Stratified (thanks to the feedback of Jeremias Berg, Jakob Nordström, Bart Bogaerts, Andy Oertel, and Dieter Vandesande). The bug led to erroneous hardening of some of the sum literals due to an incorrect estimation of the sum of the weights in lower strata.

05.03.2023 (0.1.8.dev1)

  • Added CaDiCaL 1.5.3 (thanks to Christos Karamanos).
  • Added the process module (thanks to Christos Karamanos).
  • Added a build for Python 3.11 on Win64.

xx.02.2023 (0.1.7.dev27)

  • Fixed the list of auxiliary variables reported as a result of formula negation. Added a list of literals involved in the encoding of clauses.

23.01.2023 (0.1.7.dev26)

  • Added a few more warning messages for various solvers, related to missing keyword arguments.

17.01.2023 (0.1.7.dev25)

  • Fixed a bug related to missing keyword arguments for Minisat22, MinisatGH, and Minicard.
  • Updated documentation of methods solve(), solve_limited(), propagate(), and enum_models() saying that duplicate assumption literals are forbidden.

15.01.2023 (0.1.7.dev24)

  • Added warm start mode to MapleCM.

13.01.2023 (0.1.7.dev23)

  • Fixed a typo in examples/

13.01.2023 (0.1.7.dev22)

  • Fixed a time computation bug in examples/
  • Added warm start mode to ‘m22’, ‘mgh’, ‘mc’, ‘mpl’, ‘g30’, ‘g41’, ‘gc30’, ‘gc41’.

22.11.2022 (0.1.7.dev21)

  • Made a number of minor tweaks in formula parsing.

18.11.2022 (0.1.7.dev20)

  • Fixed the patch issue on macOS Ventura.

06.07.2022 (0.1.7.dev19)

  • An attempt to fix statistics report when running in WebAssembly (type cast to Py_ssize_t).

18.06.2022 (0.1.7.dev18)

  • Fixed a couple of minor bugs in pysat.card and pysat.pb related to variable ID update.

03.06.2022 (0.1.7.dev17)

  • Addition of AtMostK constraints on the fly is added to RC2, LBX and MCSls.
  • Added support for additional hard constraints in Hitman, both in the form of clauses and AtMostK constraints.
  • Added the eMUS mode to OptUx, i.e. it can enumerate subset-minimal MUSes.
  • Added support for additional formula to be used in OptUx for stopping MUS enumeration as soon as the additional formula is covered by the set of MUSes.

22.02.2022 (0.1.7.dev16)

  • Fixed a minor issue in RC2 related to making useless iterations in core minimization.
  • Added support for WCNF+ formulas in OptUx.

04.12.2021 (0.1.7.dev15)

  • Fixed a minor bug in stratified RC2 related to model enumeration for empty formulas.
  • Updated Hitman so that it opts for plain RC2 if all weights are the same.
  • Fixed cost MUS computation in OptUx.

24.11.2021 (0.1.7.dev14)

  • Another attempt to fix the bug in topw handling if unspecified.

24.11.2021 (0.1.7.dev13)

  • Fixed a minor issue in related to handling native AM1 constraints.
  • Fixed a bug in WCNF parser, which caused incorrect top weight computation if not specified in the preamble of the file explicitly.

09.11.2021 (0.1.7.dev12)

  • Fixed a bug related to handling CNF formulas and improper updating IDPool for PB constraints in the case of no auxiliary variables.

12.10.2021 (0.1.7.dev11)

  • Fixed a bug related to meaningless bounds in cardinality constraints (both AtMost and AtLeast).

17.08.2021 (0.1.7.dev10)

  • Added cluster-based stratification to RC2.
  • Made the selection of stratification strategy in RC2 optional.

02.08.2021 (0.1.7.dev9)

  • Added proper handling of border cases when creating cardinality constraints. Done for all encodings, and both AtMostK and AtLeastK constraints.
  • Added an UnsupportedBound exception to be raised whenever pairwise, bitwise, or ladder encodings are created with the bound in $(1, N
    • 1)$.

30.07.2021 (0.1.7.dev8)

  • Fixed a bug in IDPool introduced in 0.1.7.dev7, related to None handling.

28.07.2021 (0.1.7.dev7)

  • Updated IDPool to return a new variable ID without an object.
  • Updated RC2 to support IDPool instead of self.topv.

17.07.2021 (0.1.7.dev6)

  • Modified the implemention of the am1 heuristic in RC2.

26.06.2021 (0.1.7.dev5)

  • Got rid of relaxation variables in RC2 - minor issue, which might still have affected the performance.

11.06.2021 (0.1.7.dev4)

  • Fixed compilation issues occurring for cadical on macOS >= 11.3 with the most recent version of clang. Thanks to András Salamon.

24.05.2021 (0.1.7.dev3)

  • Added a warning in enum_models() regarding unsatisfiability of the formula after model enumeration is finished.
  • Fixed a couple of bugs in FM.
  • Similar changes in other example implementations.

20.04.2021 (0.1.7.dev2)

  • Improved the sequential counters encoding based on Donald Knuth's irredundant variant, following the suggestion of Alex Healy.

31.03.2021 (0.1.7.dev1)

  • An attempt to fix compilation issues of Mergesat.

31.03.2021 (0.1.7.dev0)

  • Added basic interface to Mergesat3.
  • Ported Minicard's native cardinality support to Glucose, which resulted in solvers Gluecard3 and Gluecard4.
  • Added translation of Cadical's binary DRUP format to text-based.

25.03.2021 (0.1.6.dev16)

  • A few minor corrections in RC2, RC2Stratified, and Hitman addressing the issues related to empty formulas.

23.03.2021 (0.1.6.dev15)

  • A minor correction in OptUx related to MUS cost value.

23.03.2021 (0.1.6.dev14)

  • A minor correction in the script.

23.03.2021 (0.1.6.dev13)

  • Added a way to bootstrap LBX and MCSls for computing MCSes that include a specified subset of clauses.
  • Updated Hitman to support weighted hitting set problems.
  • Added OptUx, which is an smallest/optimal MUS extractor and enumerator that aims to replicate the performance of Forqes.

13.02.2021 (0.1.6.dev12)

  • Fixed formula dumping in other formats (see to_alien).

24.11.2020 (0.1.6.dev11)

  • Added formula dumping in SMT-LIB2 (see to_alien).

19.11.2020 (0.1.6.dev10)

  • Fixed the number of propagations ins MapleChrono.

27.09.2020 (0.1.6.dev9)

  • Fixed a bug in copying of CNFPlus and WCNFPlus objects.
  • Added an attempt to write down OPB and LP formats (likely to be buggy!).

26.09.2020 (0.1.6.dev8)

  • Fixed a bug in related to the CNFPlus iterator.

25.09.2020 (0.1.6.dev7)

  • Added an example for accum_stats().
  • Fixed a minor bug in musx example.
  • A few fixes in pysat.formula.
  • Fixed an issue in pysat.card related to non-list literals.

09.08.2020 (0.1.6.dev6)

  • Using int64_t for accum_stats().

03.08.2020 (0.1.6.dev5)

  • Fixed the bug of wrong top_id when no cardinality encoding is created.

26.07.2020 (0.1.6.dev4)

  • Accumulated stats for other solvers.
  • More enumeration-related fixes in RC2Stratified.

07.07.2020 (0.1.6.dev3)

  • Fixed RC2's enumeration of MSSes.
  • Minor changes to the patch for CaDiCaL

06.07.2020 (0.1.6.dev2)

  • Forgot to manifest the solver archives. :)

06.07.2020 (0.1.6.dev1)

  • Solver archive files are now shipped with PySAT.
  • A bit cleaner signal handling.
  • Got rid of the segmentation faults when CTRL+C'ing limited SAT calls.
  • Accumulated stats for Glucose4.1 (by Chris Jefferson)

04.07.2020 (0.1.5.dev17)

  • Removed dependency for zlib.

23.06.2020 (0.1.5.dev16)

  • Fixed a minor bug in top id handling in pysat.card reported by Pedro Bonilla.

15.06.2020 (0.1.5.dev15)

  • A few more minor changes in RC2 to fulfill the requirements of MSE 2020.

18.05.2020 (0.1.5.dev14)

  • A few minor changes in RC2 addressing a new v-line format and the top-k track.

05.05.2020 (0.1.5.dev13)

  • A few minor issues related to non-deterministic behavior of sets in Python3.

12.04.2020 (0.1.5.dev12)

  • Fixed a minor bug in garbage collector of RC2.
  • Fixed an empty-core bug in RC2 appearing in solution enumeration.

19.03.2020 (0.1.5.dev10)

  • Floating point arithmetic is now done through the decimal module to avoid precision issues.

19.03.2020 (0.1.5.dev9)

  • Minor issue fixed in RC2Stratified.

17.03.2020 (0.1.5.dev8)

  • Added support of floating point weights in WCNF and WCNFPlus.
  • Added support of negative weights.

14.03.2020 (0.1.5.dev7)

  • Another minor fix in pysat.formula related to importing py-aiger-cnf.

24.01.2020 (0.1.5.dev6)

  • Fixed a minor bug related to unknown keyword arguments passed to the constructor of Solver.

08.01.2020 (0.1.5.dev5)

  • Added support of copying CNFPlus and WCNFPlus formulas.

04.12.2019 (0.1.5.dev2)

  • Fixed yet another issue related to pysat.formula.CNFPlus and pysat.solvers.Minicard.
  • Replaced time.clock() with time.process_time() for Python 3.8 and newer.

04.12.2019 (0.1.5.dev1)

  • Added Windows support (many thanks to Rüdiger Jungbeck!).
  • Fixed a few more issues related to pysat.formula.CNFPlus and pysat.formula.WCNFPlus.

02.12.2019 (0.1.4.dev25)

  • Fixed the parser of pysat.formula.WCNFPlus formulas.
  • Fixed a bug in method append_formula for pysat.solvers.Minicard.

28.11.2019 (0.1.4.dev24)

  • Fixed signal handling in the multithreaded use of PySAT. Multiple oracles can be used at a time now.

14.11.2019 (0.1.4.dev23)

  • Fixed a minor bug in pysat.examples.lsu.

07.11.2019 (0.1.4.dev22)

  • A minor fix in pysat.formula related to importing py-aiger-cnf.

30.10.2019 (0.1.4.dev21)

  • Marked py-aiger-cnf as an optional dependency.

29.10.2019 (0.1.4.dev20)

  • The use of py-aiger is replaced by py-aiger-cnf to incapsulate the internals of py-aiger.

09.10.2019 (0.1.4.dev19)

  • Added solution optimality check in pysat.examples.lsu.
  • Added a way to update the used variable identifiers using pysat.formula.IDPool when working with pysat.card.CardEnc.* and pysat.pb.PBEnc.*.
  • Minor cosmetic changes.
  • New logo.

30.09.2019 (0.1.4.dev18)

  • Fixed a bug related to using py-aiger on Python 2.

28.08.2019 (0.1.4.dev17)

  • Updated the minimum version of py-aiger required for installation.

28.08.2019 (0.1.4.dev16)

  • CNF formulas can now be bootstrapped by Tseitin-encoding AIGER circuits. This is done with the use of the py-aiger package.

21.08.2019 (0.1.4.dev15)

  • Added rudimentary support of CaDiCaL.

04.06.2019 (0.1.4.dev13)

  • Fixed the wrong number of variables after calling methods of CardEnc.
  • Added clause iterator to CNF.
  • Calling CardEnc.*([]) returns an empty CNF formula.

25.06.2019 (0.1.4.dev12)

  • Corrected a typo in the method name WCNF.unweighted.

17.06.2019 (0.1.4.dev11)

  • Added top weight update when adding soft clauses into a WCNF.

26.05.2019 (0.1.4.dev10)

  • Added support for non-deterministic interruption, e.g. based on a timer.

17.05.2019 (0.1.4.dev9)

  • Minor fixes related to the WCNF+ support in pysat.examples.lsu, pysat.examples.lbx, and pysat.examples.mcsls.

27.04.2019 (0.1.4.dev8)

  • Made an attempt to fix the C++ library issue on MacOS.

19.04.2019 (0.1.4.dev7)

  • Fixed a couple of minor issues in pysat.examples.hitman and pysat.example.mcsls.

21.03.2019 (0.1.4.dev6)

  • Fixed a potential bug related to "deallocating None".

19.03.2019 (0.1.4.dev5)

  • Fixed an issue in propagate for the MapleChrono solver.

18.03.2019 (0.1.4.dev3)

  • Some fixes in the assumption handling of the Maple* solvers.

17.03.2019 (0.1.4.dev2)

  • Added three solvers of the Maple family: Maplesat (i.e. MapleCOMSPS_LRB), MapleCM, and MapleChrono (i.e. MapleLCMDistChronoBT).
  • A few minor fixes.

13.03.2019 (0.1.4.dev1)

  • Added pysat.pb providing access to a few PB constraints with the use of PyPBLib.
  • A number of small fixes.

28.12.2018 (0.1.3.dev25)

  • Fixed model enumerator in pysat.examples.rc2.
  • Documented pysat.examples.rc2.

01.11.2018 (0.1.3.dev24)

  • Documented a few example modules including pysat.examples.lbx, pysat.examples.mcsls, and pysat.examples.lsu.

22.09.2018 (0.1.3.dev23)

  • Added the image of the FLOC medals to the webpage.
  • Added the news section to the webpage.
  • Removed unused source code.

20.09.2018 (0.1.3.dev22)

  • Added better support for iterables in pysat.card and pysat.solvers.
  • Added documentation for examples/, examples/, examples/ and examples/

06.09.2018 (0.1.3.dev21)

  • Fixed a typo in the project description on PyPI.

30.08.2018 (0.1.3.dev20)

  • Added an implementation of the LSU algorithm for MaxSAT.
  • Fixed a bug in pysat._fileio appearing when LZMA is not present.

25.08.2018 (0.1.3.dev19)

  • Solvers can receive iterables as clauses (besides lists).
  • Fixed a minor issue in examples/

25.08.2018 (0.1.3.dev18)

  • Cosmetic changes in the documentation.

25.08.2018 (0.1.3.dev17)

  • More incremental functionality in RC2, LBX, and MCSls.
  • Added a minimal hitting set enumerator as another example.

20.08.2018 (0.1.3.dev16)

  • Fixed a problem appearing when no model exists.

19.08.2018 (0.1.3.dev15)

  • Added support for reading and writing with *zipped files.
  • Added the corresponding capabilities to the examples.

17.08.2018 (0.1.3.dev14)

  • Fixed a couple of minor issues related to Python 3 (in RC2 and iterative totalizer).

27.07.2018 (0.1.3.dev13)

  • Added support for setting variable phases (user-preferred polarities).

16.07.2018 (0.1.3.dev12)

  • Added incremetal model enumeration to RC2.
  • Fixed a couple of minor issues in LBX and MCSls.
  • Added mutilated chessboard princimple formulas for examples/

12.07.2018 (RC2)

MaxSAT solver RC2 won both unweighted and weighted categories of the main track of MaxSAT Evaluation 2018 and got two medals at FLOC 2018 Olympic Games!

image: width=270px

20.06.2018 (0.1.3.dev11)

  • Added the webpage for the toolkit.
  • The first draft of the documentation.

07.06.2018 (0.1.3.dev10)

  • Fixed a minor bug in iterative totalizer.
  • Added modes A and B to RC2 for MaxSAT evaluation 2018.

28.05.2018 (0.1.3.dev9)

  • Added a way to manually set off a previously set budget on the number of clauses or propagations.
  • Added an optional core minimization in RC2.

25.05.2018 (0.1.3.dev8)

  • Fixed long_description of the project. Corrected the GitHub reference.
  • Implemented hidden AtMost1 constraint detection in RC2.
  • Improved support for Python 3 in RC2.
  • A few more minor issues in RC2 got fixed.

23.05.2018 (0.1.3.dev7)

  • Added optional phase saving in literal propagation.
  • Fixed a bug in literal propagation.

22.05.2018 (0.1.3.dev6)

  • More fixes in literal propagation and its interface.

21.05.2018 (0.1.3.dev5)

  • A minor modification of literal propagation.

21.05.2018 (0.1.3.dev4)

  • Added literal propagation in MiniSat-like solvers, i.e. Minisat22, MinisatGH, Minicard, Glucose3, and Glucose41.

15.05.2018 (0.1.3.dev3)

  • Another attempt to fix installation. Mirrored GitHub-hosted solvers.

02.05.2018 (0.1.3.dev2)

  • Modified signal handling in pysolvers and pycard.
  • Fixed a couple of minor issues in iterative totalizer.
  • Reimplemented examples/ Each family of formulas is not a class.

10.04.2018 (0.1.3.dev1)

  • Fixed a bug in limited SAT solving, i.e. in solving within a given budget on the number of conflicts or the number of propagations.

09.04.2018 (0.1.3.dev0)

  • Improved README.rst.
  • Minor modifications in examples/
  • Added example scripts installation as executables.

08.04.2018 (0.1.2.dev9)

  • Fixed a couple of minor bugs in pysat.card and pysat.formula.

06.04.2018 (0.1.2.dev8)

  • Added a couple of optimizations to examples/ including unsatisfiable core trimming and core exhaustion.
  • Added SolverNames to simplify a solver selection.
  • An attempt to make the installation process less fragile.

03.04.2018 (0.1.2.dev7)

  • Fixed incremental mode of Glucose 4.1.
  • Added support for Minicard's native cardinality constraints in examples/
  • Added RC2 as an example of a MaxSAT solver.
  • Fixed a minor issue in iterative totalizer.

29.03.2018 (0.1.2.dev6)

  • Fixed a bug in iterative totalizer, which led to clause duplication.

28.03.2018 (0.1.2.dev5)

  • Added iterative totalizer to pysat.card.
  • Added solver download caching (i.e. a solver is not downloaded more than once).

25.03.2018 (0.1.2.dev4)

  • Added support for Glucose 4.1.

06.03.2018 (0.1.2.dev3)

  • Added examples/ illustrating the work with the pysat.formula module.
  • Added pysat.formula.IDPool, a simple manager of variable identifiers.

04.03.2018 (0.1.2.dev2)

  • Fixed a bug related to SAT oracle's timer.

02.03.2018 (0.1.2.dev1)

  • Fixed a number of issues in examples/, examples/, and examples/ for a better support of Python 3.

01.03.2018 (0.1.1.dev9)

  • Minor fixes in README.rst.

22.02.2018 (0.1.1.dev8)

  • Minor changes in pysat.card.
  • A few typos in
  • Fixed author_email in

11.02.2018 (0.1.1.dev7)