timed global protocol Fibonacci(role A, role B)
{
    rec Fib
    {
        choice at A
        {
            fibonacci(Long) from A to B within [0;1] using a and resetting ();
            fibonacci(Long) from B to A within [0;1] using a and resetting ();
            continue Fib within [0;1] using a and resetting ();
        }
        or
        {
            stop() from A to B within [0;1] using a and resetting ();
        }
    }
}