Sub MPROVE(A(), ALUD(), N, INDX(), B(), X())
    NMAX = 100
    Dim R(100)
    For I = 1 To N
        SDP = -B(I)
        For J = 1 To N
            SDP = SDP + A(I, J) * X(J)
        Next J
        R(I) = SDP
    Next I
    Call LUBKSB(ALUD(), N, INDX(), R())
    For I = 1 To N
        X(I) = X(I) - R(I)
    Next I
End Sub