The second edition of this successful textbook continues to provide a clear introduction to formal reasoning relevant to the needs of modern computer science and sufficiently exacting for practical applications. Improvements have been made throughout with many new and expanded text sections. The coverage of model-checking has been substantially updated and additional exercises are included. Internet support includes worked solutions for teacher exercises and model solutions to some student exercises. First Edition Hb (2000): 0-521-65200-6 First Edition Pb (2000): 0-521-65602-8