The complexity of facets resolved
Journal of Computer and System Sciences - 26th IEEE Conference on Foundations of Computer Science, October 21-23, 1985
GRASP: A Search Algorithm for Propositional Satisfiability
IEEE Transactions on Computers
Formal methods for the validation of automotive product configuration data
Artificial Intelligence for Engineering Design, Analysis and Manufacturing
Proceedings of the 31st ACM SIGPLAN-SIGACT symposium on Principles of programming languages
AMUSE: a minimally-unsatisfiable subformula extractor
Proceedings of the 41st annual Design Automation Conference
MUP: a minimal unsatisfiability prover
Proceedings of the 2005 Asia and South Pacific Design Automation Conference
An interpolating theorem prover
Theoretical Computer Science - Tools and algorithms for the construction and analysis of systems (TACAS 2004)
Compressing Propositional Refutations
Electronic Notes in Theoretical Computer Science (ENTCS)
Local-search Extraction of MUSes
Constraints
Data Compression for Proof Replay
Journal of Automated Reasoning
Linear-Time Reductions of Resolution Proofs
HVC '08 Proceedings of the 4th International Haifa Verification Conference on Hardware and Software: Verification and Testing
Automatic abstraction without counterexamples
TACAS'03 Proceedings of the 9th international conference on Tools and algorithms for the construction and analysis of systems
Compressing propositional proofs by common subproof extraction
EUROCAST'07 Proceedings of the 11th international conference on Computer aided systems theory
An efficient and flexible approach to resolution proof reduction
HVC'10 Proceedings of the 6th international conference on Hardware and software: verification and testing
VMCAI'10 Proceedings of the 11th international conference on Verification, Model Checking, and Abstract Interpretation
A branch-and-bound algorithm for extracting smallest minimal unsatisfiable formulas
SAT'05 Proceedings of the 8th international conference on Theory and Applications of Satisfiability Testing
Deriving small unsatisfiable cores with dominators
CAV'06 Proceedings of the 18th international conference on Computer Aided Verification
A scalable algorithm for minimal unsatisfiable core extraction
SAT'06 Proceedings of the 9th international conference on Theory and Applications of Satisfiability Testing
TACAS'10 Proceedings of the 16th international conference on Tools and Algorithms for the Construction and Analysis of Systems
IJCAR'10 Proceedings of the 5th international conference on Automated Reasoning
Hi-index | 0.00 |
Unsatisfiability proofs find many applications in verification. Today, many SAT solvers are capable of producing resolution proofs of unsatisfiability. For efficiency smaller proofs are preferred over bigger ones. The solvers apply proof reduction methods to remove redundant parts of the proofs while and after generating the proofs. One method of reducing resolution proofs is redundant resolution reduction, i.e., removing repeated pivots in the paths of resolution proofs (aka Pivot recycle). The known single pass algorithm only tries to remove redundancies in the parts of the proof that are trees. In this paper, we present three modifications to improve the algorithm such that the redundancies can be found in the parts of the proofs that are DAGs. The first modified algorithm covers greater number of redundancies as compared to the known algorithm without incurring any additional cost. The second modified algorithm covers even greater number of the redundancies but it may have longer run times. Our third modified algorithm is parametrized and can trade off between run times and the coverage of the redundancies. We have implemented our algorithms in OpenSMT and applied them on unsatisfiability proofs of 198 examples from plain MUS track of SAT11 competition. The first and second algorithm additionally remove 0.89% and 10.57% of clauses respectively as compared to the original algorithm. For certain value of the parameter, the third algorithm removes almost as many clauses as the second algorithm but is significantly faster.