Sub VANDER(X(), W(), Q(), N)
    NMAX = 100
    ZERO = 0#
    ONE = 1#
    Dim C(100)
    If N = 1 Then
        W(1) = Q(1)
    Else
        For I = 1 To N
            C(I) = ZERO
        Next I
        C(N) = -X(1)
        For I = 2 To N
            XX = -X(I)
            For J = N + 1 - I To N - 1
                C(J) = C(J) + XX * C(J + 1)
            Next J
            C(N) = C(N) + XX
        Next I
        For I = 1 To N
            XX = X(I)
            T = ONE
            B = ONE
            S = Q(N)
            K = N
            For J = 2 To N
                K1 = K - 1
                B = C(K) + XX * B
                S = S + Q(K1) * B
                T = XX * T + B
                K = K1
            Next J
            W(I) = S / T
        Next I
    End If
End Sub