start_up = proc ()
    po: stream := stream$primary_output()

    for i: int in int$from_to(1, 100) do
        out: string := ""
        if i // 3 = 0 then out := out || "Fizz" end
        if i // 5 = 0 then out := out || "Buzz" end
        if string$empty(out) then out := int$unparse(i) end
        stream$putl(po, out)
    end
end start_up