That assumes you can ask the questions at exactly the same instance of time, you'd probably need more in real life, how many more? Nothing is absolute in progr

That assumes you can ask the questions at exactly the same instance of time, you'd probably need more in real life, how many more? Nothing is absolute in programming - anyone who's tried to uniquely identify a person in a database has struck this problem. For instance there was a time when gender was part of the key for a person in a database - not the case now.