using System;

using System.Collections.Generic;

using System.Linq;

​

public class Test

{

    public static void Main()

    {

        string[] array = { "x", "y" };

        Console.WriteLine(ContainsAllItems(array, array));

    }

​

    public static bool ContainsAllItems<T>(IEnumerable<T> a, IEnumerable<T> b)

    {

        return !b.Except(a).Any();

    }

}