The discussion centers on finding a concise yet rigorous book covering key results in calculus. Serge Lang's "A First Course in Calculus" is mentioned as a potential option, though its rigor may be subjective based on past reading experiences. The book includes motivation for the chain rule proof and has epsilon-delta concepts in the appendix, but key theorems about continuous functions may not be in the main text. Another suggestion is "Introduction to Analysis" by Maxwell Rosenlicht, which is compact and affordable but may lack clarity for those not already familiar with analysis concepts. Overall, there is skepticism about finding a truly concise book that maintains rigorous standards, as shorter texts often prioritize definitions and techniques over depth.