books.google.com - This book introduces logic with an orientation towards mathematics and computing theory. The goal of this text is to teach students how to construct and write informal, but rigorous, mathematical proofs using basic set theory, recursive definitions, and mathematical induction. This book provides the...http://books.google.com/books/about/Logic_Sets_and_Recursion.html?id=V6MrCspnh9wC&utm_source=gb-gplus-shareLogic, Sets, and Recursion