My favorite way to make doing reading from a Serge Lang book less horrifying: play 'How drunk was the author while writing this section?'. It's a well known students' story that he wrote the linal textbook in one sodden weekend, but you can find proof of drunkeness in his other textbooks. For example, from A First Course in Calculus, "In this case, we use the Taylor formula for f = (a +h)."(440) Does he mean the Taylor formula for a sum which he has never mentioned and doesn't write out in full here, but just plugs into?