books.google.com - This books gives an introduction to discrete mathematics for beginning undergraduates. One of original features of this book is that it begins with a presentation of the rules of logic as used in mathematics. Many examples of formal and informal proofs are given. With this logical framework firmly in...http://books.google.com/books/about/Discrete_Mathematics.html?id=HXSjIP0OgCUC&q=classical+logic&utm_source=gb-gplus-shareDiscrete Mathematics