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Why does this happen when I verify. When I verify the sup of test1.P3 and test.P6, I get gtr < inf. What does this mean and how can I solve it? My model is as follows:

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eric
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The message means that the supremum is infinity, i.e. there is no upper bound for gtr. The reason for this is that the system can stay in the initial state indefinately, thus gtr may get arbitrary large valuation.

mariusm
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  • Thank you very much. Sorry to reply so late. In view of this problem, I still have some questions, why does system stay in the initial state indefinitely? Is it because I didn't set invariants and guards for some states? – eric Jun 15 '21 at 08:28
  • @eric the system *can* stay in the initial stay because that's how the semantics of timed automata works (it has non-deterministic choice to either stay or take a transition). The maximum delay can be controlled by an invariant and minimum is usually controlled by guards. The automaton can also synchronize. – mariusm Jun 20 '21 at 05:38
  • Thank you very much. In addition, I'm not clear about synchronization. What exactly does synchronization mean? Do the clocks of two states after synchronization advance synchronously? – eric Jun 25 '21 at 13:25
  • @eric synchronization means that two or more processes agree to execute their edges in one transition. Such edges need to agree on channels. Nothing happens to clocks unless they get updated by the edges that are being executed. Please read the Uppaal tutorial. – mariusm Jun 25 '21 at 20:39