52. A Markov chain is said to be a tree process if

(i) Pij > 0 whenever Ñâ > 0.

(ii) for every pair of states i and y, / 5* y, there is a unique sequence of distinct states / = /0, / º , , i„ = j such that Pik.i*+i>0> * = 0 , 1 , . . . , Ë - 1 In other words, a Markov chain is a tree process if for every pair of distinct states / and j there is a unique way for the process to go from / to j without reentering a state (and this path is the reverse of the unique path from j to /). Argue that an ergodic tree process is time reversible.