using System;

public class Program

{

    public class X {

        public int? A {get;set;}

    }

    public static void Main()

    {

        X x= null;

        X y = new X();

        X z = new X{A = 1};

        if (x is {A:null}) {

            Console.WriteLine("X: yep");

        }

        if (y is {A:null}) {

            Console.WriteLine("Y: yep");

        }

        if (z is {A:2}) {

            Console.WriteLine("Z.A is 2");

        }

        if (z is {A:1}) {

            Console.WriteLine("Z.A is 1");

        }

    }

}