  Priced timed automata provide a natural model for quantitative analysis of
real-time systems and have been successfully applied in various scheduling and
planning problems. The optimal reachability problem for linearly-priced timed
automata is known to be PSPACE-complete. In this paper we investigate priced
timed automata with more general prices and show that in the most general
setting the optimal reachability problem is undecidable. We adapt and implement
the construction of Audemard, Cimatti, Kornilowicz, and Sebastiani for
non-linear priced timed automata using state-of-the-art theorem prover Z3 and
present some preliminary results.
