using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Started");

             var list = new List<classBase>();

            list.Add(new classBase());

            list.Add(new classDerived());

​

            list.Select(x => x.Prop1Base == 2);

            Console.ReadLine();

    }

}

​

    class classBase

    {

        public int Prop1Base { get; set; }

​

        public int Prop2Base { get; set; }

​

    }

​

    class classDerived : classBase

    {

        public int Prop1Derived { get; set; }

​

        public int Prop2Derived { get; set; }

​

    }

​