Expanding on your #1, I think they could use some more definitions. As you say, they use "map" in its functional programming sense before defining it, but I thi

Expanding on your #1, I think they could use some more definitions. As you say, they use "map" in its functional programming sense before defining it, but I think more confusing is this one: > A category in category theory is a collection of objects and morphisms between them. What is a "morphism"? I think this is a great starting point though, which could use some expansion.