In probability theory, Kolmogorov's zero-one law, named in honor of Andrey Nikolaevich Kolmogorov, treats of probabilities of certain "tail events" defined in terms of infinite sequences of random variables. Suppose
Kolmogorov's zero-one law states that the probability of any tail event is either zero or one.
In a book published in 1909, Émile Borel stated that if a dactylographic monkey hits typewriter keys randomly forever, it will eventually type every book in France's National Library. That is a special case of this zero-one law.