The book isn't quite clear about this, so let me ask...
If the traffic lights in the direction I'm going are red, but I have a green arrow in the direction I'm going, that means that — given that I make sure to yield for traffic going across — I can enter the intersection and turn, right?
What if there are no arrows and I want to go that way? Do the regular rules for yielding and right of way apply then, or am I simply not allowed to drive that way?