> First, it is explained in the text above it. A minor correction: the explanation for this heuristic was added later. (I first opened this in a tab, and then

> First, it is explained in the text above it. A minor correction: the explanation for this heuristic was added later. (I first opened this in a tab, and then didn't read the tab till much later. I also wondered about the heuristic and didn't think to hit reload till I saw your reply.) But you're right, there is certainly nothing ungenerous from Norvig here. Quite the opposite.