timed global protocol Booking(role C, role A, role S)
{
    rec Loop {
        choice at C
        {
            choice at C
            {
                Yes() from C to A within [0;1] using a and resetting ();
                Yes() from A to S within [0;1] using a and resetting ();
                Payment(int) from C to S within [0;1] using a and resetting ();
                Ack() from S to C within [0;1] using a and resetting ();
            }
            or
            {
                No() from C to A within [0;1] using a and resetting ();
                No() from A to S within [0;1] using a and resetting ();
            }
            Bye() from C to A within [0;1] using a and resetting ();
        }
        or
        {
            Query(int) from C to A within [0;1] using a and resetting ();
            Quote(int) from A to C within [0;1] using a and resetting ();
            Dummy() from A to S within [0;1] using a and resetting ();   // Dummy
            continue Loop within [0;1] using a and resetting ();
        }
    }
}