anchor.diff:  class function BigInteger.Log2(const Value: BigInteger): Double;
   begin
     Result := Log(Value, 2.0);
  +end;
  +
  +function BigInteger.Log(Base: Double): Double;
  +begin
  +  Result := Log(Self, Base);
  +end;
  +
  +function BigInteger.Log10: Double;
  +begin
  +  Result := Log(Self, 10.0);
  +end;
  +
  +function BigInteger.Log2: Double;
  +begin
  +  Result := Log(Self, 2.0);
   end;
   
   class operator BigInteger.LogicalNot(const Value: BigInteger): BigInteger;
  
positive.code:     // -- Math functions --
  
      /// <summary>Returns the absolute value of the value in the BigInteger.</summary>
      class function Abs(const Value: BigInteger): BigInteger; static;
  
      /// <summary>Returns the bit length, the minimum number of bits needed to represent the value, excluding
      ///   the sign bit.</summary>
  
negative.code:     class function GreatestCommonDivisor(const Left, Right: BigInteger): BigInteger; static;
  
      /// <summary>Returns the natural logarithm of the BigInteger value.</summary>
      class function Ln(const Value: BigInteger): Double; overload; static;
  
      /// <summary>Returns the natural logarithm of the current BigInteger.</summary>
      function Ln: Double; overload;
  
      /// <summary>Returns the logarithm to the specified base of the BigInteger value.</summary>
      class function Log(const Value: BigInteger; Base: Double): Double; overload; static;
  
      /// <summary>Returns the logarithm to the specified base of the current BigInteger.</summary>
      function Log(Base: Double): Double; overload;
  
      /// <summary>Returns the logarithm to base 2 of the BigInteger value.</summary>
      class function Log2(const Value: BigInteger): Double; overload; static;
  
      /// <summary>Returns the logarithm to base 2 of the current BigInteger.</summary>
      function Log2: Double; overload;
  
      /// <summary>Returns the logarithm to base 10 of the BigInteger value.</summary>
      class function Log10(const Value: BigInteger): Double; overload; static;
  
      /// <summary>Returns the logarithm to base 10 of the current BigInteger.</summary>
      function Log10: Double; overload;
  
      /// <summary>Returns the larger of two specified values.</summary>
      class function Max(const Left, Right: BigInteger): BigInteger; static;
  