interface ISensor
{
  in void enable();
  in void disable();

  out void triggered();
  out void disabled();

  behaviour b
  {
    enum States {
        Disabled,
        Enabled,
        Disabling,
        Triggered
    };
    States state = States.Disabled;

    [state.Disabled]
    {
      on enable:
      {
        state = States.Enabled;
      }
      on disable:
        illegal;
    }
    [state.Enabled]
    {
      on enable:
        illegal;
      on disable:
      {
        state = States.Disabling;
      }
      on optional:
      {
        triggered;
        state = States.Triggered;
      }
    }
    [state.Disabling]
    {
      on enable, disable:
        illegal;
      on inevitable:
      {
        disabled;
        state = States.Disabled;
      }
    }
    [state.Triggered]
    {
      on enable:
        illegal;
      on disable:
      {
        state = States.Disabling;
      }
    }
  }
}