Table of Contents

1. Introduction; 2. The basic theory of memory structures; 3. Equivalence relations; 4. A plethora of simple examples; 5. The effectiveness theorems; 6. Fragments of lisp; 7. Derivations and transformations; 8. The Robson marking algorithm and applications; 9. Programs as data and the eval function; 10. Editing data efficiently; 11. Conclusions; Bibliography.