What are the best books about Common Lisp?

One common criticism of the Monty Hall problem is that the assumptions about the host's behavior are not specified, such as when the original question was posed to Marilyn vos Savant in 1990. In that instance, it was not specifically stated that the host would always open another door, or always offer a choice to switch, or even that the host must open a door containing a goat. The criticism is that without these behaviors specifically stated, the player does not have an assurance that switching is always the best option. One cannot conclude the best course of action unless these assumptions are explicitly stated in the problem.