using System;

public class Program

{

    public static void Main()

    {

        DateTime? nullableDate = null;

        DateTime? otherNullableDate = null;

        DateTime nonNullableDate = DateTime.Now;

        if(nonNullableDate <= nullableDate){

            Console.WriteLine("Can compare and non-nullable is less than nullable.");

        }else{

            Console.WriteLine("Can compare and nullable is less than non-nullable.");

        }

        if(nonNullableDate == otherNullableDate){

            Console.WriteLine("Nullable dates are equal when both null.");

        }else{

            Console.WriteLine("Nullable dates are not equal when both null.");

        }

    }

}