"If you are not familiar with this relatively new research about the foundations and and minimal assumptions needed to develop the massive mathematical structure, this provides a good informal guideline."<b>---Adhemar Bultheel, <i>European Mathematical Society</i></b>
"John Stillwell’s book gives a clear and engaging introduction to an intriguing area of mathematics: reverse mathematics."<b>---Martyn Prigmore, <i>Mathematics Today</i></b>
"The book is rich in examples and historical perspectives, is clearly argued and immaculately presented."<b>---Graham Hoare, <i>Mathematical Gazette</i></b>
"Filling an important niche, this book gives readers a good picture of the basics of reverse mathematics while suggesting several directions for further reading and study. It provides a context for the questions investigated by reverse mathematics and makes an extended argument for their significance within contemporary mathematical practice."—Denis Hirschfeldt, University of Chicago
"Reverse mathematics is a major research direction in the foundations of mathematics and mathematical logic, and the insights obtained from reverse mathematics will interest a wide mathematically minded audience. Stillwell's book is self-contained and includes much background material in analysis, mathematical logic, combinatorics, and computability. I heartily commend this very readable and accessible book."—Stephen Simpson, Vanderbilt University