gistfile1.cs

[ServiceContract]

public interface IHello

{

    [OperationContract]

    void SayHello(string name);

}

[ServiceContract]

public interface IGoodbye

{

    [OperationContract]

    void SayGoodbye(string name);

}

public class GreetingService : IHello, IGoodbye // service implements both contracts

{

    public void SayHello(string name)

    {

        Console.WriteLine("Hello {0}", name);

    }

    public void SayGoodbye(string name)

    {

        Console.WriteLine("Goodbye {0}", name);

    }

}