Properties of the sequence of random variables $-(1/n) \log p$ are obtained for an arbitrary, not necessarily ergodic or stationary, information source. These permit an elementary combinatorial proof of the AEP (asymptotic equipartition property).
"An Elementary Proof of the AEP of Information Theory." Ann. Math. Statist. 31 (2) 452 - 456, June, 1960. https://doi.org/10.1214/aoms/1177705908