vc = proc (n, base: int) returns (int, int)
    p: int := 0
    q: int := 1
    while n ~= 0 do
        p := p * base + n // base
        q := q * base
        n := n / base
    end
    num: int := p
    denom: int := q
    while p ~= 0 do
        p, q := q // p, p
    end
    return(num/q, denom/q)
end vc

print_frac = proc (po: stream, num, denom: int)
    if num=0 then
        stream$puts(po, "   0")
    else
        stream$puts(po, " ")
        stream$putright(po, int$unparse(num), 2)
        stream$puts(po, "/")
        stream$putright(po, int$unparse(denom), 2)
    end
end print_frac

start_up = proc ()
    po: stream := stream$primary_output()
    for base: int in int$from_to(2,5) do
        stream$puts(po, "base " || int$unparse(base) || ":")
        for i: int in int$from_to(0, 9) do
            n, d: int := vc(i, base)
            print_frac(po, n, d)
        end
        stream$putl(po, "")
    end
end start_up