Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A great reference book on constraint processing

I've found this book to be invaluable for my research so far. My area of research isn't in constraint processing itself, but some of the problems I've worked on have had hard constraints needing to be addressed, and this book has made it easy to do so.This book is very well written, clearly explaining the various topics. I've had no problems understanding any of the material presented. It does a great job of covering the various techniques for dealing with constraints. It gives many examples and provides detailed pseudocode for the various algorithms, making them easy to implement.I would highly recommend this book to anyone needing a book on constraint processing.