Apostol's calculus texts were my first experience with 'real' proof-based mathematics, and I also learned real analysis through his Mathematical Analysis book. Good times; his books taught me a lot.
He wrote with clarity and conciseness; when I read Apostol it always seemed like not a single word was added unnecessarily. I highly suggest picking up his books, and am sad to see that he passed away.
He wrote with clarity and conciseness; when I read Apostol it always seemed like not a single word was added unnecessarily. I highly suggest picking up his books, and am sad to see that he passed away.