Jean-Raymond Abrial, a consultant at Steria in Paris, provides an informal introduction to B, a debugging technology designed to help industrial practitioners build software systems more effectively. Unlike classical debugging techniques that rely on execution, B focuses on mathematical proofs to catch errors early in the development process. This shift from execution to properties and proofs can be challenging for some developers, who are accustomed to thinking in terms of data and actions. Abrial emphasizes the importance of rewriting requirement documents to focus on the properties of the future system, rather than the pseudo-implementation details. This involves reorienting requirements towards precise statements of the system's static and dynamic aspects, which can take several months for large systems.Jean-Raymond Abrial, a consultant at Steria in Paris, provides an informal introduction to B, a debugging technology designed to help industrial practitioners build software systems more effectively. Unlike classical debugging techniques that rely on execution, B focuses on mathematical proofs to catch errors early in the development process. This shift from execution to properties and proofs can be challenging for some developers, who are accustomed to thinking in terms of data and actions. Abrial emphasizes the importance of rewriting requirement documents to focus on the properties of the future system, rather than the pseudo-implementation details. This involves reorienting requirements towards precise statements of the system's static and dynamic aspects, which can take several months for large systems.