Конфигурация log4net для консольного приложения

Проблема с большинством из вышеперечисленных заключается в том, что они будут работать с точностью около 25! (12! С 32-битными значениями) или просто переполнение. Вот реализация c # для преодоления этих ограничений!

class Number
{
  public Number ()
  {
    m_number = "0";
  }

  public Number (string value)
  {
    m_number = value;
  }

  public int this [int column]
  {
    get
    {
      return column < m_number.Length ? m_number [m_number.Length - column - 1] - '0' : 0;
    }
  }

  public static implicit operator Number (string rhs)
  {
    return new Number (rhs);
  }

  public static bool operator == (Number lhs, Number rhs)
  {
    return lhs.m_number == rhs.m_number;
  }

  public static bool operator != (Number lhs, Number rhs)
  {
    return lhs.m_number != rhs.m_number;
  }

  public override bool Equals (object obj)
  {
     return this == (Number) obj;
  }

  public override int GetHashCode ()
  {
    return m_number.GetHashCode ();
  }

  public static Number operator + (Number lhs, Number rhs)
  {
    StringBuilder
      result = new StringBuilder (new string ('0', lhs.m_number.Length + rhs.m_number.Length));

    int
      carry = 0;

    for (int i = 0 ; i < result.Length ; ++i)
    {
      int
        sum = carry + lhs [i] + rhs [i],
        units = sum % 10;

      carry = sum / 10;

      result [result.Length - i - 1] = (char) ('0' + units);
    }

    return TrimLeadingZeros (result);
  }

  public static Number operator * (Number lhs, Number rhs)
  {
    StringBuilder
      result = new StringBuilder (new string ('0', lhs.m_number.Length + rhs.m_number.Length));

    for (int multiplier_index = rhs.m_number.Length - 1 ; multiplier_index >= 0 ; --multiplier_index)
    {
      int
        multiplier = rhs.m_number [multiplier_index] - '0',
        column = result.Length - rhs.m_number.Length + multiplier_index;

      for (int i = lhs.m_number.Length - 1 ; i >= 0 ; --i, --column)
      {
        int
          product = (lhs.m_number [i] - '0') * multiplier,
          units = product % 10,
          tens = product / 10,
          hundreds = 0,
          unit_sum = result [column] - '0' + units;

        if (unit_sum > 9)
        {
          unit_sum -= 10;
          ++tens;
        }

        result [column] = (char) ('0' + unit_sum);

        int
          tens_sum = result [column - 1] - '0' + tens;

        if (tens_sum > 9)
        {
          tens_sum -= 10;
          ++hundreds;
        }

        result [column - 1] = (char) ('0' + tens_sum);

        if (hundreds > 0)
        {
          int
            hundreds_sum = result [column - 2] - '0' + hundreds;

          result [column - 2] = (char) ('0' + hundreds_sum);
        }
      }
    }

    return TrimLeadingZeros (result);
  }

  public override string ToString ()
  {
    return m_number;
  }

  static string TrimLeadingZeros (StringBuilder number)
  {
    while (number [0] == '0' && number.Length > 1)
    {
      number.Remove (0, 1);
    }

    return number.ToString ();
  }

  string
    m_number;
}

static void Main (string [] args)
{
  Number
    a = new Number ("1"),
    b = new Number (args [0]),
    one = new Number ("1");

  for (Number c = new Number ("1") ; c != b ; )
  {
    c = c + one;
    a = a * c;
  }

  Console.WriteLine (string.Format ("{0}! = {1}", new object [] { b, a }));
}

FWIW: 10000! более 35500 символов.

Skizz