The Structure of Typed Programming Languages describes the fundamental syntactic and semantic features of modern programming languages, carefully spelling out their impacts on language design. Using classical and recent research from lambda calculus and type theory, it presents a rational reconstruction of the Algol-like imperative languages such as Pascal, Ada, and Modula-3, and the higher-order functional languages such as Scheme and ML. The text is based on the premise that although few programmers ever actually design a programming language, it is important for them to understand the structuring techniques. His use of these techniques in a reconstruction of existing programming languages and in the design of new ones allows programmers and would-be programmers to see why existing languages are structured the way they are and how new languages can be built using variations on standard themes. Unique in its tutorial presentation of higher-order lambda calculus and intuitionistic type theory, this book is designed for use in a first or second course on principles of programming languages. It assumes a basic knowledge of programming languages and mathematics.