Public Sub CheckPower()
 
            Dim x, y, z1, z2 As Double
 
            For i As Integer = 0 To 1000000
                x = RandDbl() : y = RandDbl()
                z1 = x ^ y
                z2 = System.Math.Pow(x, y)
                If Double.IsNaN(z1) Then
                    If Not Double.IsNaN(z2) Then Stop
                Else
                    If z1 <> z2 Then Stop
                End If
            Next i
        End Sub
 
 
        Public Function RandDbl() As Double
            'Rückgabe eines zufälligen Double-Wertes
            'incl. Sonderwerte und Ganzzahl-Rundung
 
            Static rndm As System.Random
            If rndm Is Nothing Then rndm = New System.Random(12345)
 
            Dim p As Double = rndm.NextDouble, v As Double
            If p < 0.1 Then
                p = rndm.NextDouble
                If p < 0.25# Then Return Double.NegativeInfinity
                If p < 0.5# Then Return Double.PositiveInfinity
                If p < 0.75# Then Return Double.NaN
                Return 0.0#  'exakt 0
            Else
                v = rndm.NextDouble * 100     'Zufallszahl
                p = rndm.NextDouble
                If p <= 0.5# Then v = -1.0# * v 'negative Zahl
                p = rndm.NextDouble
                If p < 0.1# Then v = Math.Round(v, 0) 'Ganzzahl
                Return v
            End If
        End Function