Transitions and Trees

Cover of book

This is the official homepage for the book which has been published in April 2010 by Cambridge University Press.

What this book is about

Structural operational semantics is a simple, yet powerful mathematical theory for describing the behaviour of programs in an implementation-independent manner. This book provides a self-contained introduction to structural operational semantics, featuring semantic definitions using big-step and small-step semantics of many standard programming language constructs, including control structures, structured declarations and objects, parameter mechanisms and procedural abstraction, concurrency, nondeterminism and the features of functional programming languages. Along the way, the text introduces and applies the relevant proof techniques, including forms of induction and notions of semantic equivalence (including bisimilarity). Thoroughly class-tested, this book has evolved from lecture notes used by the author over a 10-year period at Aalborg University to teach undergraduate and graduate students. The result is a thorough introduction that makes the subject clear to students and computing professionals without sacrificing its rigour. No experience with any specific programming language is required.

Read more in the Cambridge UP catalogue.

How and where to buy the book

This book ought to be available from every respectable on-line bookstore, and it is available as both a hardcover and as a paperback. Here are a few suggestions (with links to the hardcover edition):

A moment's thought

A list of hints to the mini-problems found in the text is available her (as a PDF file).


Here is an errate sheet (in PDF format).


To contact me,  send me an e-mail . The address is


Pilen ved træets rod (aka the book in Danish)

Denne bog findes også på dansk under titlen Pilen ved træets rod. Indholdet er præcis det samme som i den engelsksprogede udgave. Den er kun udgivet til brug i min egen undervisning. Men skriv til mig for at høre, hvordan du kan anskaffe dig et eksemplar. Danske forlag, der vil udgive bogen, er selvfølgelig også meget velkomne til at skrive.