Understanding Non-reducible Modal Transition Systems by Davide Basile

The author introduces Non-reducible Modal Transition Systems (NMTS) and their refinement relation to address the limitations of traditional modal refinement in preserving non-deterministic behavior across implementations. The core argument is that NMTS refinement ensures the preservation of non-reducible non-determinism, which is violated by implementations accepted through modal refinement but rejected by NMTS refinement.