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CSharp · Console

/Program.cs

interface IA
{
    void a();
}

interface IB : IA
{
    void b();
}

interface IC : IB
{
    void c();
}

interface ID : IA, IB, IC
{
    void d();
}

public class D : ID
{
  public void a(){}
  public void b(){}
  public void c(){}
  public void d(){}
}

public class Program
{
	public static void Main()
	{
		var d = new D();
		d.a();
		d.b();
		d.c();
		d.d();
		IA ia = d;
		ia.a();
		IB ib = d;
		ib.b();
		IC ic = d;
		ic.c();
	}
}