using System;

​

delegate void ArDelegate(int a, int b);

​

public class ArithematicOperation {

     public static void Add(int a, int b) {

      Console.WriteLine("{0} + {1} = {2}", a, b, a + b);

     }

     public static void Sub(int a, int b) {

      Console.WriteLine("{0} - {1} = {2}", a, b, a - b);

     }

}

​

public class DelegateProgram {

​

     public static void Main() {

          ArDelegate del = new ArDelegate(ArithematicOperation.Add);

          //multicast delegate here

          del += new ArDelegate(ArithematicOperation.Sub);

          del(4, 2);

​

          del -= new ArDelegate(ArithematicOperation.Sub);

          del(1, 9);

     }

​

}