'The presentation is a pleasure to read, and the careful selection of topics leads the reader on a very direct route to some of the most fascinating problems and results in the theory of von Neumann algebras … an excellent introduction at graduate level to current research in this field.' Monatshefte für Mathematik

• 1. Factors; 2. Subfactors and index; 3. Some basic facts; 4. The principal and dual graphs; 5. Commuting squares; 6. Vertex and spin models.