"First book-length exposition of the denotational (or `mathematical' or `functional') approach to the formal semantics of programming languages (in contrast to `operational' and `axiomatic' approaches). Treats various kinds of languages, beginning with the pure-lambda-calculus and progressing through languages with states, commands, jumps, and assignments. This somewhat discursive account is a valuable compilation of results not otherwise available in a single source." -- American Mathematical Monthly