He remembered her at age five, building towers of wooden blocks, then knocking them down with a shriek of joy. He remembered her at fourteen, crying in the kitchen because a boy had called her ugly. He remembered the last fight—the one about her mother, about his emotional absence, about the word conditional used as a weapon.
She reached out a thin hand. He took it. Her fingers were cold. And then, for the first time in eleven years, he did something that was not in any of his textbooks: he remembered. markov chain norris
Norris defines a discrete-time Markov Chain $(X_n) {n \geq 0}$ as a random process satisfying the : $$P(X {n+1} = j \mid X_n = i, X_{n-1} = i_{n-1}, \dots, X_0 = i_0) = P(X_{n+1} = j \mid X_n = i)$$ In plain English: The future depends on the past only through the present. Once you know where you are right now, the history of how you got there is irrelevant to where you go next. He remembered her at age five, building towers