Abstract We introduce an updated version of the Pono model checker. Pono is a versatile SMT-based model checker that integrates multiple verification algorithms and interfaces with a wide range of SMT solvers through a solver-agnostic back end. It emphasizes usability, offering support for commonly used input formats and providing C++ and Python APIs for programmatic access. The new version 2.0 introduces several important new features, including support for liveness properties, new interpolation-based safety-checking engines, a new VMT-LIB front end, and a number of usability and performance enhancements. An evaluation of the new version demonstrates significant improvements in performance over its previous version and comparable performance to other state-of-the-art model checkers. These results highlight Pono 2.0’s effectiveness as a general-purpose and easily extensible verification platform.

Racetrack memory is a promising new non-volatile memory technology, especially because of the density of its 3D implementation. However, for 3D racetrack to reach its potential, certain reliability issues must be overcome. Prior work used per-track encoding to tolerate the shift errors that are unique to racetrack, but no solutions existed for tolerating both shift errors and bit flip errors. We introduce Foosball Coding, which combines per-track coding for shift errors with a novel across-track coding for bit flips. Moreover, our per-track coding scheme methodically explores the design of inter-codeword delimiters and introduces the novel concept of multi-purpose delimiters, in which the existence of multiple delimiter options can be used to provide additional information.