Instruct: Classify Amazon reviews into positive or negative sentiment
Query: an excellent introductory logic textbook

As a college philosophy teacher I have tried many textbooks for teaching informal logic. I am very happy with this book. It presents the material thoroughly and clearly and has tons of useful exercises. I don't need the chapters on symbolic logic for the course I teach, but the material on informal and Aristotelian logic is working very nicely. The publisher maintains an interactive website with additional exercises and review material for students. My students use it and appreciate it.