Unsatisfiability Proofs for Horn Solving
Additional information
Authors
Otoni R.,
Blicha M.,
Rivera M. B.,
Eugster P. T.,
Kofron̆ J.,
Sharygina N.
Type
Book chapter
Year
2025
Language
English
Abstract
Many verification tools currently rely on logic solvers as backend reasoning engines. Despite playing such a pivotal role, bugs are not uncommon in the complex codebases of these solvers. Validating their results is thus critical, with correctness witnesses often being used for this end. Output validation for constrained Horn clauses (CHC) solvers is not a well explored topic though, especially in regards to unsatisfiability results. This is a significant issue, given that CHC solvers are being increasingly employed in verification tooling. To address it, we propose an approach to validate CHC unsatisfiability results based on independently checkable proofs. Our approach is generic in regards to the solving algorithm, preprocessing steps, and exact proof format used, and works by first producing a coarse-grained proof during solving and then instantiating it into a suitable proof format by adding missing details, at which point the instantiated proof can be checked by an independent proof checker. We instrumented a state-of-the-art CHC solver to generate proofs in the Alethe format and performed a large-scale evaluation. Our results indicate that proofs can be produced with minimal overhead, can be efficiently checked, and have tractable sizes.
Book
Lecture Notes in Computer Science
Publisher
Springer Nature Switzerland
Pages (or article number)
67-87
ISBN
9783031906527, 9783031906534
ISSN
0302-9743, 1611-3349
Diffusion
License
License undefined
Visibility
Private
