using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("    A,     B, Result");

        Boolean?[] as_ = [true, false, null];

        Boolean?[] bs_ = [true, false, null];

        foreach (var a in as_) {

            foreach (var b in bs_) {

                Console.WriteLine($"{Format(a)}, {Format(b)}, {Format(!a & (!b ?? true))}");

            }

        }

    }

​

    public static String Format(Boolean? value)

    {

        if (value is null) {

            return " null";

        }

        return (Boolean) value ? " true" : "false";

    }

}