Function EX(X)
    R1 = 0.00107857
    R2 = -0.00976004
    R3 = 0.05519968
    R4 = -0.24991055
    R5 = 0.99999193
    R6 = -0.57721566
    T1 = 8.5733287401
    T2 = 18.059016973
    T3 = 8.6347608925
    T4 = 0.2677737343
    S1 = 9.5733223454
    S2 = 25.6329561486
    S3 = 21.0996530827
    S4 = 3.9584969228
    If X < 1# Then
        AAA = (R1 * X + R2) * X + R3
        EX = ((AAA * X + R4) * X + R5) * X + R6 - Log(X)
    Else
        Y# = (((X + T1) * X + T2) * X + T3) * X + T4
        W# = (((X + S1) * X + S2) * X + S3) * X + S4
        EX = (Y# / W#) / (Exp(X) * X)
    End If
End Function