Max-SAT is the proble
m of finding an assign
ment
mini
mizing the nu
mber of unsatisfied clauses in a CNF for
mula. We propose a resolution-like calculus for Max-SAT and prove its soundness and co
mpleteness. We also prove the co
mpleteness of so
me refine
ments of this calculus. Fro
m the co
mpleteness proof we derive an exact algorith
m for Max-SAT and a ti
me upper bound.
We also define a weighted Max-SAT resolution-like rule, and show how to adapt the soundness and completeness proofs of the Max-SAT rule to the weighted Max-SAT rule.
Finally, we give several particular Max-SAT problems that require an exponential number of steps of our Max-SAT rule to obtain the minimal number of unsatisfied clauses of the combinatorial principle. These results are based on the corresponding resolution lower bounds for those particular problems.