Elan is a nicely designed educational programming language loosely derived from Algol 68. It inherits from Algol 68 such features and characteristics as unbounded-length strings (texts) and an “expression orientation” whereby statement-like constructs can yield values. It includes some important extra features, such as packets for data abstraction and free-form refinements. Refinements allow all the abstraction levels of an algorithm to coexist explicitly within a single program coding. On the other hand, Elan excludes many useful features such as procedure nesting, unions, pointers, parallel processing, and bounds-independent array types; the language thus cannot be considered a serious software engineering tool. Implementations of Elan are available at low cost for today’s most common microcomputer models.

This book, which is actually the first of two volumes, is a textbook on introductory programming. It places great emphasis on the use of Elan’s refinement construct to perform top-down program construction. Coverage of some of the language’s facilities, such as structures and packets, is deferred to the second volume, where bottom-up programming is apparently emphasized.

The topics discussed range from algorithms in everyday life to the replacement of recursion by iteration. There are two chapters on the fundamentals of algorithms, four on the basic data types of Elan, one on control structures, one on arrays, one on files, one on procedures, three on recursion, and one on backtrack programming. There are ample examples of varying length and difficulty. The selection of exercises at the ends of chapters is rather limited, and no solutions are given. There are appendices containing details of Elan’s syntax, its standard packets, and the use of its programming environment. Finally, there is a nine-page index that, unfortunately, gives section numbers instead of page numbers.

Although the book’s European origin is quite apparent, it is well suited to a worldwide readership. Its standard of English writing and editing is imperfect but acceptable.

With regard to both the topic organization and the programming language employed, I feel that this text would be a very good vehicle for teaching an introductory programming course. Instructors and committees with the courage to contemplate using a non-widely-used language in such a course would be well advised to consider adoption of this book.