An SMT Algorithm for Direct Model Search: Implementation and Experimentation

SMT solvers have traditionally been based on the DPLL(T) algorithm, where the driving force behind the procedure is a DPLL search over truth valuations. This traditional framework allows for a degree of modularity in the treatment of theory solvers. Over time, theory solvers have become more and more closely integrated into the DPLL process, and consequently less and less modular. In this paper, we present a DPLL-like algorithm for SMT solving which unifies theory solving and DPLL search into a single process, directly searching for a model over the space of variable valuations. As a case study, we analyze its application to continuous domain linear arithmetic, present implementation techniques and some experimention with difference logic.