Textbook in PDF format Software errors can lead to catastrophic consequences, from financial losses to threats to human safety. As a result, rigorous methods for software development and validation have become increasingly critical. Program verification, a key area of formal methods, provides mathematical tools and techniques to ensure that software behaves as intended. This book provides a comprehensive introduction to program verification, combining theoretical foundations with practical applications using real-world tools. It offers a self-contained overview of propositional logic and first-order reasoning with theories, followed by a study of Hoare-style program logic with annotations and the generation of verification conditions. The use of Frama-C’s WP plug-in for verifying C programs annotated with the ACSL specification language, including safety properties, is also covered. This revised and expanded second edition incorporates recent advances in formal methods and program verification, integrating new techniques, tools, and exercises to equip readers with the skills necessary for rigorous software development. Program verification is the area of Computer Science that studies mathematical methods for checking that a program conforms to its specification. It is part of the broader area of formal methods, which groups together very heterogeneous rigorous approaches to systems and software development. Program verification is concerned with properties of code, which can be studied in more than one way. From methods based on logic, in particular the combined use of a program logic and first-order theories, to other approaches like software model checking; abstract interpretation; and symbolic execution. This book is a self-contained introduction to program verification using logic-based methods, requiring only a basic understanding of standard mathematical concepts familiar to any Computer Science student. It begins by highlighting the growing importance of program verification and formal approaches in software development, and by providing an overview of formal methods to offer context for the verification techniques discussed in the subsequent chapters. The book then presents a self-contained introduction to propositional logic and first-order reasoning with theories, followed by an in-depth study of program verification that integrates both theoretical and practical aspects—from program logic to the use of a realistic tool for verifying C programs, including the generation of verification conditions and safety properties. Rigorous Software Development is ideal for Computer Science students, researchers in formal methods, and software engineers seeking a deeper understanding of program verification techniques and tools. It equips readers with the knowledge needed to apply rigorous methods in practice while providing a solid foundation for the evolving Introduction An Overview of Formal Methods Tools and Techniques Propositional Logic First-Order Logic Hoare Logic Generating Verification Conditions Safety Properties Procedures and Contracts Specifying C Programs Verifying C Programs