namespace N
{
    public class A {}
    public class B {}
}

namespace N
{
    public class B {}
    public class C {}
}

class Test
{
    N.A a; // Ok
    N.B b; // Fehler
    N.C c; // Ok
}

csc /r:a1.dll /r:a2.dll test.cs

extern alias X;
extern alias Y;

class Test
{
    X::N.A a;
    X::N.B b1;
    Y::N.B b2;
    Y::N.C c;
}

csc /r:X=a1.dll /r:Y=a2.dll test.cs

using System;
using System.Collections.Generic;
using System.Text;

namespace HighscoreTest
{
    public class Highscore : IComparable
    {
        private string _name = String.Empty;
        private int _score = 0;

        public string Name
        {
            get { return this._name; }
            set { this._name = value; }
        }

        public int Score
        {
            get { return this._score; }
            set { this._score = value; }
        }

        public Highscore(string name, int score)
        {
            this._name = name;
            this._score = score;
        }

        public override string ToString()
        {
            return this._name.PadRight(20, ' ') + this._score;
        }

        #region IComparable Members

        public int CompareTo(Highscore other)
        {
            if (this._score.CompareTo(other._score) == 0)
                return this._name.CompareTo(other._name);
            else
                return this._score.CompareTo(other._score) * (-1);
       }

        #endregion
    }
}

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
using System.Diagnostics;

namespace HighscoreTest
{
    class Program
    {
        static void Main(string[] args)
        {
            List highscoreList = new List();
            highscoreList.Add(new Highscore("Norbert2", 17));
            highscoreList.Add(new Highscore("Norbert1", 17));
            highscoreList.Add(new Highscore("Norbert3", 3));
            highscoreList.Add(new Highscore("Karl", 3));

            highscoreList.Sort();

            Debug.WriteLine("Highscore");
            Debug.WriteLine("--------------------");
            foreach(Highscore hscore in highscoreList)
                Debug.WriteLine(hscore);

        }
    }
}

public interface IPerson
{
    string Firstname { get; set; }
    string Lastname { get; set; }
    DateTime Birthday { get; }
}

public class Person : IPerson
{
    private string _firstname = null;
    private string _lastname = null;
    private DateTime _birthday;

    public string Firstname
    {
        get { return this._firstname; }
        set { this._firstname = value; }
    }

    public string Lastname
    {
        get { return this._lastname; }
        set { this._lastname = value; }
    }

    public DateTime Birthday
    {
        get { return this._birthday; }
        internal set { this._birthday = value; }
    }
}

class Program
{
    static void Function<T>(int x, T y)
    {
        Console.WriteLine("Function 1");
    }

    static void Function<T>(T x, long y)
    {
        Console.WriteLine("Function 2");
    }

    static void Main()
    {
        Function<int>(5, 324);
        Function<byte>(5, 324);
        Function(5, 324);
        Console.WriteLine();
    }
}