We study cdcl-cuttingplanes, Open-WBO, and Sat4j, three successful solvers from the
Pseudo-Boolean Competition 2016, and evaluate them by performing experiments on
crafted benchmarks designed to be trivial for the cutting planes (CP) proof system underlying
pseudo-Boolean (PB) proof search but yet potentially tricky for PB solvers. Our experiments
demonstrate severe shortcomings in state-of-the-art PB solving techniques. Although our
benchmarks have linear-size tree-like CP proofs, and are thus extremely easy in theory, the …

… Extended Rational Hypothesis Pseudo-Boolean solvers have potential to run fast when
there are small, strong backdoors to rational unsatisfiability … Extended Rational Hypothesis
Pseudo-Boolean solvers have potential to run fast when there are small, strong backdoors to
rational unsatisfiability … Instance hard for resolution ⇒ Open-WBO has no chance Even
“easy versions of hard formulas” can be dead-hard (subset cardinality, even colouring)
Open-WBO can be very good when cardinality encoding works well (vertex cover: 2-CNF + big …