Negotiations model concurrent systems through multiparty interactions between processes. Each interaction has possible outcomes that determine the processes' subsequent behaviour. In this talk, I will introduce negotiations and their extension to local-timed negotiations, where processes have local clocks and timing constraints, advance time independently, and synchronize their local times at selected interactions. We studied reachability in this model: can a specified interaction outcome occur?

I will explain how differences between local times can encode unbounded counters, making reachability undecidable in general. I will then describe decidable fragments, including synchronization-free and always-synchronizing local-timed negotiations, and systems in which every feasible finite interaction sequence admits a realization with uniformly bounded differences between local times. If time permits, I will briefly explain how a connectivity condition on time-synchronizing interactions guarantees such a bound.

Bio: Adwitee Roy is a research associate at the Tata Institute of Fundamental Research, with research interests in automata, logic, and games. Her doctoral research at Chennai Mathematical Institute, supervised by B. Srivathsan, studied reachability and decidability in concurrent systems with local time.