v1.5.1

Added

• Introduced a new FormulaHelper class for small utility methods on formulas
• Added a new NNF predicate

Fixed

• Fixed an unspecified behaviour in SATPredicate
• Fixed a small performance issue in the new backbone solver
• Fixed a bug in a special case of the CNF transformation of a pseudo-Boolean constraint

v1.5.0

Added

• Algorithm & data structures for efficiently computing backbones of formulas
• Data structures for UBTrees in order to efficiently identify sub- and supersets
• CNF and DNF subsumption as formula transformations
• Backbone simplifier (compute and propagate the backbone of a formula)
• A new sorted formula formatter which respects a given variable ordering when printing formulas

Changed

• Minor code refactorings and improvements

Deprecated

• Deprecation of CleaneLing - this solver will be removed in future versions.

v1.4.1

Changed

• Some refactorings for unit tests on Windows regarding encodings
• The Quine-McCluskey implementation does not yield CNF auxiliary variables anymore

Fixed

• Fixed a minor bug in the generation of incremental cardinality constraints

v1.4.0

Added

• BDD package (based on Buddy) for creating, manipulating, and writing BDDs
  • Creation of BDDs from LogicNG formulas
  • CNF, DNF transformation of BDDs
  • Restriction, existential & universal quantifier elimination
  • Model counting & enumeration
  • Different static variable ordering heuristics (FORCE, DFS, BFS, MinMax)
  • Writing BDDs in the GraphViz .dot format
• Quine-McCluskey Implementation for minimizing canonical DNFs
• New formula transformation for anonymizing formulas

Changed

• Internal parser and IO improvements. Variables can now start with a digit.

v1.3.1

Added

• New formula transformation which imports formulas in another formula factory

Changed

• Huge performance boost in the model enumeration of MiniSat

Fixed

• Small bugfix for a trivial case in DRUP

v1.3

Added

• MiniSat and Glucose have a new option for proof tracing. A DRUP implementation stores all the necessary information for generating a proof for unsatisfiable
  formulas after
  solving them. The new method can be found in the SAT solver class: unsatCore()
• A new simplifier which applies the distributive law was added: DistributiveSimplifier

Changed

• Unsat Cores are now parametrized with the proposition type

Fixed

• Some minor bug-fixes in handling corner cases of cardinality and pseudo-Boolean constraints

v1.2

Added

• Introduced an extended formula factory which is able to return to a previously saved state and delete old formulas (and get them garbage collected)
• A simple data structure for generic graphs including algorithms for connected components and maximal cliques
• Improved IO (Writers for formulas, Dimacs CNFs, and graphs)

Changed

• SAT solvers can now track the currently known variables
• Updated to ANTLR 4.7

Fixed

• Various smaller bugfixes