Overall, though, little can be skipped entirely without potential difficulties later
on. A few sections, which are marked with an asterisk, can be omitted without
loss to later material. Most of the material, however, is essential and must be
covered.
The fifth edition of this text introduces a substantial amount of new material.
While the presentation in the fourth edition has been retained with only minor
modifications, two appendices have been added. The first is an entire chapter on
finite-state transducers, Appendix A. While transducers play no significant role
in formal language theory, they are important in other areas of computer science,
such as digital design. Students can benefit from an early exposure to this
subject; if time permits it is worthwhile to do so. Due to the similarity with finite
accepters, this involves few new concepts.
I also added an introduction to JFLAP, an interactive software tool that I feel
is of great help in both learning the material and in teaching this course. JFLAP
implements most of the ideas and constructions in this book. It not only helps
students visualize abstract concepts, but it is also a great time-saver. Many of the
exercises in this bookrequire creating structures that are complicated and that
have to be thoroughly tested for correctness. JFLAP can reduce the time required
for this by an order of magnitude. Appendix B gives a brief introduction to
JFLAP and the CD that comes with the bookexpands on this. I very much
recommend the use of JFLAP for both students and instructors.
Peter Linz