program knuth_shuffle;
    setrandom(0);

    array := [1..10];
    print("Before shuffling:", array);
    shuffle(array);
    print("After shuffling: ", array);

    proc shuffle(rw tup);
        loop for i in [1..#tup-1] do
            j := random [i+1..#tup];
            [tup(i), tup(j)] := [tup(j), tup(i)];
        end loop;
    end proc;
end program;