Modern SAT solvers are frequently embedded as sub-reasoning engines into more complex tools for addressing problems beyond the Boolean satisfiability problem. Examples include solvers for Satisfiability Modulo Theories (SMT), combinatorial problems, or model enumeration and counting. In such use cases, the SAT solver is often able to provide relevant information beyond the satisfiability answer. Further, domain knowledge of the embedding system (e.g., symmetry properties or theory axioms) would be beneficial for the CDCL search, but cannot be efficiently represented in clausal form.
In this talk, I will present a general interface to inspect and influence the internal behaviour of CDCL SAT solvers. Our goal is to capture the most essential functionalities that are sufficient to simplify and improve use cases that require a more fine-grained interaction with the SAT solver than provided via the standard IPASIR interface. I will present our experiments, where we extend CaDiCaL with our proposed interface and evaluate it on two representative use cases: enumerating graphs within the SAT modulo Symmetries framework (SMS), and as the main CDCL(T) SAT engine in the SMT solver cvc5.

This is a joint work with Aina Niemetz, Mathias Preiner, Markus Kirchweger, Stefan Szeider, and Armin Biere.

Video Recording