On timed alternating simulation for concurrent timed games

Abstract : We address the problem of alternating simulation refinement for concurrent timed games (TG). We show that checking timed alternating simulation between TG is EXPTIME-complete, and provide a logical characterization of this preorder in terms of a meaningful fragment of a new logic, TAMTL*. TAMTL* is an action-based timed extension of standard alternating-time temporal logic ATL*, which allows to quantify over strategies where the designated coalition of players is not responsible for blocking time. While for full TAMTL*, model-checking TG is undecidable, we show that for its fragment TAMTL, corresponding to the timed version of ATL, the problem is instead decidable and in EXPTIME.