“…Some authors use the term "semi-Markov kernel" of discrete-time SM processes for P(J n+1 = j, T n+1 − T n = k|J n = i) (see, e.g., [1,7,8,10,19,20,22]). Other authors use the term "semi-Markov kernel" of discrete-time SM processes for P(J n+1 = j, T n+1 − T n ≤ k|J n = i) (see, e.g., [21,23,[26][27][28]), while the quantity P(J n+1 = j, T n+1 − T n = k|J n = i) can have several names, for instance semi-Markov core matrix. In this article, we used this second terminology.…”