One of the 20th century's most original mathematicians, Menger taught students of many backgrounds. His radical revision of the traditional text presents pure and applied calculus in a clarified conceptual frame, offering a thorough understanding of theory as well as the ability to use calculus as a tool. 1955 edition.
I liked the emphasis on the composition of functions, the consistent notation, and the difference between free and bound variables. But in some places, it felt like I was reading Wittgenstein.