I'm looking at my poor, mistreated old 4th Edition as I type. What memories it stirs! What despair! What dorm-room walls it was hurled against, on the eves of so many exams, and how I abused and cursed it for being a REFERENCE BOOK and not an INTRODUCTORY CALCULUS TEXTBOOK as my professors fantasized it to be when they required us to buy it! Thank you, faithful friend. We both endured, you and I. At least I didn't fail calculus, and you still have a cover and are legible. Yes, we endured.