using System;
class ExpDemo
{
public static void Main()
{
UseLnExp(9.9);
}
static void UseLnExp(double arg)
{
Console.WriteLine(
"\n Math.Exp(Math.Log({0})) == {1:E16}\n" +
" Math.Log(Math.Exp({0})) == {2:E16}",
arg, Math.Exp(Math.Log(arg)), Math.Log(Math.Exp(arg)) );
}
}