Publications [#363586] of Sayan Mukherjee

Papers Published

1. Gastin, P; Mukherjee, S; Srivathsan, B, Reachability in timed automata with diagonal constraints, Leibniz International Proceedings in Informatics, LIPIcs, vol. 118 (August, 2018), ISBN 9783959770873 [doi]
   (last updated on 2025/04/11)

   Abstract:
   We consider the reachability problem for timed automata having diagonal constraints (like x − y < 5) as guards in transitions. The best algorithms for timed automata proceed by enumerating reachable sets of its configurations, stored in a data structure called “zones”. Simulation relations between zones are essential to ensure termination and e ciency. The algorithm employs a simulation test Z Z which ascertains that zone Z does not reach more states than zone Z, and hence further enumeration from Z is not necessary. No e ective simulations are known for timed automata containing diagonal constraints as guards. We propose a simulation relation dLU for timed automata with diagonal constraints. On the negative side, we show that deciding Z dLU Z is NP-complete. On the positive side, we identify a witness for Z dLU Z and propose an algorithm to decide the existence of such a witness using an SMT solver. The shape of the witness reveals that the simulation test is likely to be e cient in practice.