My book is written, as befits such easy material, in merciless telegram style ("Axiom," "Definition," "Theorem," "Proof," occasionally "Preliminary Remark")... I hope I have written this book in such a way that a normal student can read it in two days. And then (since he already knows the formal rules from school) he may forget its contents.

Grundlagen der Analysis [Foundations of Analysis] (1930) Preface for the Teacher, as quoted by Eli Maor, Trigonometric Delights (2013)