Apply TLA+ to real-world problems and gain the building blocks to get started with your own specifications. This book is a practical, comprehensive resource on TLA+ programming with rich, complex examples. Practical TLA+ shows you how to use TLA+ to specify a complex system and test the design itself for bugs, the way that Amazon and Microsoft handle their new systems. You'll learn how even a short TLA+ spec can find critical bugs. Start by getting your feet wet with an example of TLA+ used in a bank transfer system to see how it helps you design, test, and build a better application. Then, get some fundamentals of TLA+ operators, logic, functions, PlusCal, models, and concurrency. You'll also discover advanced TLA+ specific syntax and see how it works with concurrency combined with some temporal logic. Finally, you'll put what you learn into practice with four working case study applications.