I've read that Mark Kac proved a very beautiful theorem which says that, for a stationary, discrete-valued stochastic process, the expected recurrence time of a finite trajectory is just the reciprocal of the probability of encountering the trajectory in the first place.
I could not find it in this version.
Do you know where I can read that (please do not say in the original text of Kac, because I found it and did not recognize it there).
I found the statement only for markov chains.
