I'm studying RL with Sutton and Barto's book. I'd like to ask about the order of execution of a statement in the algorithm below.
Here, $W$ (importance sampling ratio) is updated at the end of the
But, I think that updating should be located after calculating $G$ (the return) and before updating $C(s,a)$ (cumulative of $W$). This seems to be right considering the second picture below, which I found in http://incompleteideas.net/book/first/ebook/node56.html.
Is Sutton and Barto's book wrong? Or the two algorithms in Sutton and Barto's book and seconds picture are actually the same, and I am wrong? Is there any difference between the two when implemented? If I am wrong, can you explain the reason?