A Single-Instance Incremental SAT Formulation of Proof- and Counterexample-Based Abstraction

This paper presents an efficient, combined formulation of two widely used abstraction methods for bit-level verification: counterexample-based abstraction (CBA) and proof-based abstraction (PBA). Unlike previous work, this new method is formulated as a single, incremental SAT-problem, interleaving CBA and PBA to develop the abstraction in a bottom-up fashion. It is argued that the new method is simpler conceptually and implementation-wise than previous approaches. As an added bonus, proof-logging is not required for the PBA part, which allows for a wider set of SAT-solvers to be used.