raiph

    sub MAIN                         #= Print fibonacci values.
        (*@argv);                    #= eg 10 20 prints 55 6765

    print .[ @argv ]                 # print fibonacci values.
      given
        0, 1, 1, 2, 3, 5,            # First fibonacci 
    values.
        sub fib ( $m, $n )           # Fibonacci generator
                { $m + $n } ... Inf  # to compute the rest.**

    .say for [\**] 2,3,4

    4                          #           4
    81                         #      3 ** 4
    2417851639229258349412352  # 2 ** 3 ** 4

    sub double(Int $x) { $x * 2 }
    double '42'

    SORRY! Error while compiling ...

    Calling double(Str) will never work with declared signature (Int $x)
        (Int $x)

    sub date-range(Date $from, Date $to) { $from..$to }

    say date-range '2000-01-01', '2023-08-21';

    sub date-range(Date() $from, Date() $to) { $from..$to }

    sub date-range(Date(Str) $from, Date(Str) $to) { $from..$to }

    use Physics::Measure :ALL;

    # Define a distance and a time
    d = 42m; say d;     # 42 m (Length)
    t = 10s; say t;     # 10 s (Time)

    # Calculate speed and acceleration
    u = d / t; say u;   # 4.2 m/s (Speed)
    a = u / t; say a;   # 0.42 m/s^2 (Acceleration)

    # As a special treat it allows working with measurement errors:
    d = 10m ± 1;
    t = 8s ± 2;
    say d / t           # 1.25m/s ±0.4