Foundations of Computer Science

This book has been taken out of print by W. H. Freeman. You are welcome to use it if you like. We believed in 1992 it was the way to introduce theory in Computer Science, and we believe that today.

--- Al Aho and Jeff Ullman


The Book | Materials | Gradiance | Errata

PDF's of the Book

Supplementary Materials

Gradiance Package Available

Gradiance is offering a free trial of its automated homeworks for the topics covered by this book. These homeworks are designed as a teaching aid rather than an assessment tool. Students get advice when they make a mistake and are encouraged to try working on the same problem(s) until they get them right. If you would like to try the system gratis for your class, make yourself an account at Then, send email to sup port @grad iance .com (ignore the blanks in that email address, of course) telling us your login and that you would like to try the discrete-math product. You can find manuals for instructors, students, and question-authors at

Special offer for students: Until June 30, 2009, we have made use of the Gradiance materials available for students whose instructors are not using the system. Make yourself an account on, and then sign up for the class 8CD5ED01. You will be able to work 31 selected homeworks, and will get advice when you make an error. The only difference is that we cannot reveal solutions, because these assignments are open indefinitely.

Errata Sheet

We are going to try to maintain errata. Please see The Errata Sheet. If you find an unreported error, please send email to ullman at gmail dot com.