begin
    integer procedure factorial(n);
    integer n;
    begin
        integer fact, i;
        fact := 1;
        for i := 2 step 1 until n do
            fact := fact * i;
        factorial := fact
    end;
    integer f; outtext("factorials:"); outimage;
    for f := 0, 1, 2, 6, 9 do begin
        outint(f, 2); outint(factorial(f), 8); outimage
    end
end