Function CHEBEV(A, B, C(), M, X)
    If (X - A) * (X - B) > 0# Then Print "X not in range."
    D = 0#
    DD = 0#
    Y = (2# * X - A - B) / (B - A)
    Y2 = 2# * Y
    For J = M To 2 Step -1
        SV = D
        D = Y2 * D - DD + C(J)
        DD = SV
    Next J
    CHEBEV = Y * D - DD + 0.5 * C(1)
End Function