Departmental Papers (CIS)

Document Type

Conference Paper

Date of this Version

July 2004


Postprint version. Published in Lecture Notes in Computer Science, Volume 3142, Automata, Languages and Programming, (ICALP 2004), pages 122-133.
Publisher URL:


Weighted timed automata are timed automata annotated with costs on locations and transitions. The optimal game-reachability problem for these automata is to find the best-cost strategy of supplying the inputs so as to ensure reachability of a target set within a specified number of iterations. The only known complexity bound for this problem is a doubly-exponential upper bound. We establish a singly-exponential upper bound and show that there exist automata with exponentially many states in a single region with pair-wise distinct optimal strategies.



Date Posted: 22 December 2005