Another excellent exposition by John Stilwell of more-than-high-school mathematics, with no further requirement. A must for all those who like to
read enjoyable texts on such foundational topics, but reject the all-pervasive "Proposition/Proof/That's it, Figure-it-out-yourself/Proposition..." style on math books. For the rest of us. If "Elements of Number Theory" is recommended before diving into Dedekind's "Theory of Algebraic Integers", this one is great to prepare yourself for Emil Artin.

Thanks again, John.