Not sure if the authors will read this or not but I beg of you, please put a table of notation in the forward. The Sutton and Barto Reinforcement Learning book did that for basically every notation that wasn't basic algebra and it's been extremely helpful.

Just labeling things I had never seen before, like indicator functions, was extremely valuable.

Especially for this kind of book that is introducing mathematics to people from a broad background - I think it's important to understand how much of an impediment not knowing notation is by sight. Trying to Google or search for notation is a nightmare.