using System;

public class Program

{

    public static void Main()

    {

        bool? nullableBoolTrue = true;

        if (nullableBoolTrue == true) { Console.WriteLine("nullableBoolTrue: If"); } // true

        else { Console.WriteLine("nullableBoolTrue: Else"); } // false or null

        bool? nullableBoolFalse = false;

        if (nullableBoolFalse == true) { Console.WriteLine("nullableBoolFalse: If"); } // true

        else { Console.WriteLine("nullableBoolFalse: Else"); } // false or null

        bool? nullableBoolNull = null;

        if (nullableBoolNull == true) { Console.WriteLine("nullableBoolNull: If"); } // true

        else { Console.WriteLine("nullableBoolNull: Else"); } // false or null

    }

}