' version 16-09-2015
' compile with: fbc -s console

Function agm(a As Double, g As Double) As Double

    Dim As Double t_a

    Do
        t_a = (a + g) / 2
        g = Sqr(a * g)
        Swap a, t_a
    Loop Until a = t_a

    Return a

End Function

' ------=< MAIN >=------

Print agm(1, 1 / Sqr(2) )

' empty keyboard buffer
While InKey <> "" : Wend
Print : Print "hit any key to end program"
Sleep
End