Exact Max-SAT solvers for over-constrained problems

Exact Max-SAT solvers for over-constrained problems

We present a new generic problem solving approach for over-constrained problems based on Max-SAT. We first define a Boolean clausal form formalism, called soft CNF formulas, that deals with blocks of clauses instead of individual clauses, and that allows one to declare each block either as hard (i.e., must be satisfied by any solution) or soft (i.e., can be violated by some solution). We then p...

Improved Exact Solvers for Weighted Max-SAT

We present two new branch and bound weighted Max-SAT solvers (Lazy and Lazy) which incorporate original data structures and inference rules, and a lower bound of better quality.

A Two-Phase Exact Algorithm for MAX-SAT and Weighted MAX-SAT Problems

We describe a two phase algorithm for MAX{SAT and weighted MAX{ SAT problems. In the rst phase, we use the GSAT heuristic to nd a good solution to the problem. In the second phase, we use an enumera-tion procedure based on the Davis{Putnam{Loveland algorithm, to nd a provably optimal solution. The rst heuristic stage improves the performance of the algorithm by obtaining an upper bound on the m...

Exact Algorithms for MAX-SAT

The maximum satisfiability problem (MAX-SAT) is stated as follows: Given a boolean formula in CNF, find a truth assignment that satisfies the maximum possible number of its clauses. MAX-SAT is MAX-SNP-complete and received much attention recently. One of the challenges posed by Alber, Gramm and Niedermeier in a recent survey paper asks: Can MAX-SAT be solved in less than 2n “steps”? Here, n is ...

Exact Algorithms for MAX-SAT