1. Sometimes the ability to answer a question depends as much on knowing the limits of knowledge as it does on the facts themselves. For example, suppose databases A and B both contain a complete list...

1.
Sometimes the ability to answer a question depends as much on knowing the limits of

knowledge as it does on the facts themselves. For example, suppose databases A and B both contain a complete list of employees who belong to the company’s health insurance program, but only database A is aware that the list is complete. What could database A conclude about a member who was not on its list that database B could not?