function fwd_diff_n(sequence s, integer order)
    if order>=length(s) then ?9/0 end if
    for i=1 to order do
        for j=1 to length(s)-1 do
            s[j] = s[j+1]-s[j]
        end for
        s = s[1..-2]
    end for
    return s
end function

constant s = {90, 47, 58, 29, 22, 32, 55, 5, 55, 73}
for i=1 to 9 do
    ?fwd_diff_n(s,i)
end for